Role In Testicular Germ Cell Tumor Research Articles

Identification of testicular cancer immune infiltrates and novel immune cell subtypes.

Testicular germ cell tumors (TGCT) are the most common type of testicular cancer, comprising 90%-95% of cases and representing the most prevalent solid malignancy in young adult men. Immune infiltrates play important regulatory roles in tumors, but their role in TGCT remains unclear. Molecular subtyping is a promising way to provide precisely personalized treatment and avoid unnecessary toxicities. This study investigated immune infiltrates, key biomarkers, and immune subtyping of TGCT. In GSE3218, 24 differentially expressed immune genes (immDEGs) were identified. A new risk signature consisting of six immDEGs was developed using these genes. Individuals in the high-risk group had poor overall survival (OS) (hazard ratio of 4.61 and P-value <0.001). We validated the six-immDEGs risk signature in pure seminoma and mixed TGCT types. Two distinct immune patterns (Cluster 1 and Cluster 2) were identified using the ConsensusClusterPlus, and Cluster 1 possessed an unfavorable OS compared to Cluster 2 (hazard ratio, 2.56; P <0.001). Cluster 1 patients had significantly lower naive B cells, memory B cells, plasma cells, naive CD4 T cells, gamma delta T cells, and activated dendritic cells than Cluster 2 patients. Genes relating to the WNT signaling pathway, TGF-β signaling pathway, antigen processing and presentation, and NK cell-mediated cytotoxicity were associated with TGCT. STC1 was elevated in TGCT tissues, and its high expression showed advanced clinicopathological characteristics and poor prognosis of TGCT. Our findings may contribute to increased understanding of the onset and progression of TGCT.

Brachyury, a driver of epithelial mesenchymal transition, as an independent prognostic factor in high-grade testicular germ cell tumors.

e16039 Background: The T-box transcription factor Brachyury has been considered a cancer-specific marker and a novel oncotarget in solid tumors. Brachyury overexpression has been described in various cancers, being associated with epithelial-mesenchymal transition, metastasis and poor prognosis. However, its clinical association with testicular germ cell tumor (TGCT) is unknown. Methods: We analyzed the expression of Brachyury both at protein and transcript levels in a series of 96 TGCT samples and by in silico analysis, respectively. Additionally, we investigated the clinical significance of Brachyury in TGCT. Results: Brachyury protein showed to be over-represented in 89.6% (86/96) of TGCT cases with nuclear staining in 24% (23/96) of them. Microarray expression analysis in two independent cohorts of TGCTs showed similar results with increased levels of Brachyury in TGCTs and metastasis compared with normal testis. Clinically, Brachyury nuclear staining was statistically associated with event-free survival (p = 0.04) and overall survival (p = 0.01) in intermediate/high-risk TGCTs. Multivariate analysis showed that Brachyury nuclear subcellular localization was an independent predictor of poor prognosis (HR: 3.56, p = 0.06). Conclusions: These results indicate that Brachyury plays an oncogenic role in TGCTs and its subcellular localization in the nucleus is a potential novel biomarker of poor prognosis and an oncotarget for intermediate/high-risk TGCTs treatment.

MiR‑223‑3p regulates cell growth and apoptosis via FBXW7 suggesting an oncogenic role in human testicular germ cell tumors.

miR-223-3p is deregulated in several tumor types and plays an important role in tumorigenesis and progression. However, its role in the pathogenesis of testicular germ cell tumor (TGCT) remains uncharacterized. We previously demonstrated that miR-223-3p expression was increased in TGCTs compared with normal testes (NT), suggesting that miR-223-3p may have an oncogenic role in TGCT. Using published dataset and The Cancer Genome Atlas database, we validated higher miR-223-3p expression in TGCTs than NT, and found a negative correlation between miR-223-3p and FBXW7 mRNA expression levels. Using both gain- and loss-of-function experiments, we show that miR-223-3p regulates FBXW7 protein expression, cell growth and apoptosis in TGCT cell lines. Additionally, we demonstrate that ectopic expression of the full-length coding sequence of FBXW7 could rescue the cell growth and apoptotic effects mediated by miR-223-3p. Our findings suggest an oncogenic role for miR-223-3p in TGCT, which promotes cell growth and inhibits apoptosis through repression of FBXW7.

Abstract 1348: Association between genetic variation at the AKT1 and PTEN genes, and in the 8q24 locus, and the risk of testicular germ cell tumor.

Abstract Background There is strong evidence that genetic variation influences the risk of testicular germ cell tumor (TGCT). The oncogene AKT1, tumor suppressor gene PTEN and the 8q24 locus play important roles in cancer development, and investigation of their role in TGCT is warranted. Methods We investigated the association between risk of TGCT and genetic variation in the AKT1 and PTEN genes, and the 8q24 locus in a Norwegian-Swedish case-parent study. We included 831 triads, 474 dyads and 712 singletons, and 26 single nucleotide polymorphisms (SNPs) were genotyped. First, triads and dyads were included in a likelihood-based association test. To increase the statistical power, case singletons and 3922 unrelated controls from the Swedish TwinGene project were included in a single test for association. Interaction terms were included in the statistical model to examine if the allelic effect on TGCT risk was modified by histological subgroup, country of origin or parent of origin. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated and Bonferroni correction (Pbonf) was used to adjust for multiple testing. Results In the case-parent triad analyses, none of the 26 SNPs were significantly associated with TGCT. Of the 23 SNPs investigated in the combined study, one SNP in the PTEN gene, the rs11202586, remained associated with TGCT risk after adjusting for multiple testing (OR=1.16, 95% CI=1.06-1.28, Pbonf=0.040). We found no difference in risk according to histological subgroup, parent of origin or between countries. Conclusions Our findings suggest that genetic variation in the PTEN gene influences the risk of TGCT. Table. Odds ratios (ORs) for associations between polymorphisms in AKT1, PTEN and 8q24 locus and TGCT risk in the combined case-parent/case-control study. Gene Gene name SNP Allele1* Allele2 Genomic position CHR OR 95% CI P Pbonf# AKT1 v-akt murine thymoma viral oncogene homolog 1 rs2494731 C G 104308725 14 0.93 0.86–1.01 0.071 1.000 rs2494739 C T 104318034 0.96 0.83–1.11 0.594 1.000 rs2494752 A G 104334653 0.95 0.81–1.11 0.502 1.000 rs4983387 A G 104339273 1.07 0.95–1.22 0.283 1.000 PTEN phosphatase and tensin homolog rs1234212 C T 89598872 10 0.99 0.92–1.07 0.824 1.000 rs11202586 C T 89602004 1.16 1.06–1.28 0.002 0.040 rs1234221 A C 89606459 0.97 0.89–1.06 0.537 1.000 rs1234220 A G 89635453 1.16 1.03–1.31 0.018 0.414 rs1234219 A G 89639557 1.09 0.95–1.25 0.221 1.000 rs2299939 A C 89647130 1.04 0.95–1.15 0.386 1.000 rs12357281 C G 89690651 1.05 0.91–1.20 0.534 1.000 rs2248293 C T 89697245 0.95 0.88–1.03 0.233 1.000 rs926091 C T 89711392 0.91 0.82–1.02 0.105 1.000 8q24 locus rs7008482 G T 126336812 8 0.91 0.84–0.99 0.029 0.674 rs13254738 A C 128173525 1.02 0.94–1.10 0.707 1.000 rs6983561 A C 128176062 0.98 0.80–1.19 0.815 1.000 rs16901979 A C 128194098 0.94 0.78–1.15 0.566 1.000 rs6983267 G T 128482487 0.98 0.91–1.05 0.548 1.000 rs7000448 C T 128510352 0.97 0.90–1.05 0.424 1.000 rs1447295 A C 128554220 0.99 0.88–1.11 0.864 1.000 rs4242382 A G 128586755 1.00 0.89–1.13 0.986 1.000 rs7017300 A C 128594450 0.94 0.85–1.05 0.266 1.000 rs7837688 G T 128608542 1.06 0.94–1.19 0.333 1.000 * Reference allele # Bonferroni correction (P multiplied by the number of total SNPs analyses, n = 23). Citation Format: Kristine E. Andreassen, Wenche Kristiansen, Robert Karlsson, Elin L. Aschim, Olav Dahl, Sophie D. Fosså, Hans-Olov Adami, Fredrik Wiklund, Trine B. Haugen, Tom Grotmol. Association between genetic variation at the AKT1 and PTEN genes, and in the 8q24 locus, and the risk of testicular germ cell tumor. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1348. doi:10.1158/1538-7445.AM2013-1348

Novel epigenetically deregulated genes in testicular cancer include homeobox genes and SCGB3A1 (HIN‐1)

Testicular germ cell tumours (TGCTs) are classified into two main histological subgroups: seminomas and non-seminomas. The latter comprise several subtypes: embryonal carcinomas, yolk sac tumours, choriocarcinomas, and teratomas. These embryonal and extra-embryonal-like differentiation lineages represent a caricature of early normal development, and inactivation of gene expression through promoter hypermethylation may therefore be of particular importance in germ cell tumourigenesis. The promoter methylation status of ten candidate genes-CDH13, DLX6, EMX2, HOXA9, HOXB5, MSX1, MSX2, RASSF1A, RUNX3, and SCGB3A1 (alias HIN-1)-was assessed by methylation-specific PCR in seven intratubular germ cell neoplasias and 55 primary TGCTs. Furthermore, by a discovery-based global approach, comparing cDNA microarray expression profiles of two germ cell tumour cell lines before and after treatment with the demethylating agent 5-aza-2'-deoxycytidine, a gene list of potentially epigenetic targets was identified, from which CGGBP1, CGRRF1, SMARCC2, SORBS1, and XPA were analysed further. Overall, the non-seminomas were significantly more often methylated than were seminomas (p < 0.001). The three most frequently methylated genes among this subtype were SCGB3A1 (54%), RASSF1A (29%), and HOXA9 (26%). CDH13 and HOXB5 were methylated at low frequencies (10-15%), and EMX2, MSX1, RUNX3, SORBS1, and XPA only rarely (<10%). In conclusion, this study has identified several novel epigenetically deregulated target genes in TGCT development, including homeobox genes and SCGB3A1, suggesting that epigenetic inactivation of key genes in normal development also has an important role in TGCTs.

Microsatellite Instability in Germ Cell Tumors of the Testis and Ovary

Objectives. Widespread replication-type error (RER) is a genetic alteration that has been observed in many different neoplasms and has been associated with defective DNA repair activity. There are conflicting data regarding the role that this type of genetic instability plays in the development and progression of adult germ cell tumors.Methods. Universal amplification was performed on 104 paired specimens of tumor and constitutional DNA isolated from adult male and female germ cell tumors, in addition to subpopulations of carcinoma in situ (CIS), the precursor of testicular germ cell tumors (TGCTs). Preamplified DNA samples of TGCTs and ovarian germ cell tumors (OGCTs) were assayed for the presence of RER at 78 and 64 microsatellite loci, respectively.Results. RER was observed at a single microsatellite locus in 7 of 24 individual testicular germ cell tumors, including subpopulations of CIS isolated from one of these patients. There was some evidence of RER clustering for microsatellite loci mapping to the short arm of chromosome 12. Genetic instability was more frequent in OGCTs, with widespread RER observed at 38 of 64 microsatellite loci. These alterations were noted in 12 of 36 malignant OGCTs showing RER at 1 or more loci, including 3 OGCTs demonstrating RER at more than 6 separate microsatellite loci.Conclusions. The pathogenetic significance of genetic instability in germ cell tumors remains uncertain, although the results of this study suggest a lesser role in TGCTs compared to that in OGCTs.

Allele loss of tumour suppressor genes on chromosome 17 in human testicular germ cell tumours

The molecular genetics of testicular germ cell tumours (TGCT) are still largely unknown. We investigated 20 TGCT tumours for allelic losses (LOH) of tumour supressor genes BRCA1, TP53 and of THRA1 on chromosome 17. We observed an overall loss of 50% for the whole chromosome. Detailed deletion mapping revealed no losses for the BRCA1 gene, 42% LOH for THRA1 and 11% allelic loss for the region telomeric to BRCA1. We observed 11% LOH for TP53. Our results suggest that allelic losses of BRCA1 and TP53 genes do not play a pivotal role in TGCT but that dysfunction of THRA1 or tumour suppressor gene(s) in this region may have an impact in the development of this cancer.