Rare inactivating PDE11A variants associated with testicular germ cell tumors

Genome-Wide DNA Methylation Analysis and Functional Validation of Litter Size Traits in Jining Grey Goats

DNA methylation (DNAm) is associated with the reproductive system. However, the genetic mechanism through which DNAm regulates gene expression and thus affects litter size in goats is unclear. Therefore, in the present work, genome-wide DNAm profiles of HP and LP Jining Grey goat ovary tissues were comprehensively analyzed via WGBS, and RNA-Seq data were combined to identify candidate genes associated with litter size traits in the Jining Grey goat. Finally, BSP and RT-qPCR were used to verify the sequencing results of the key genes. Notably, the DNMT genes were downregulated at the expression level in the HP group. Both groups exhibited comparable levels of methylation. A total of 976 differentially methylated regions (DMRs) (973 DMRs for CG and 3 DMRs for CHG) and 310 differentially methylated genes (DMGs) were identified in this study. Through integration of WGBS and RNA-Seq data, we identified 59 differentially methylated and differentially expressed genes (DEGs) and ultimately screened 8 key DMGs (9 DMRS) associated with litter size traits in Jining Grey goats (SERPINB2: chr24_62258801_62259000, NDRG4: chr18_27599201_27599400, CFAP43: chr26_27046601_27046800, LRP1B. chr2_79720201_79720400, EPHA6: chr1_40088601_40088800, TTC29: chr17_59385801_59386000, PDE11A: chr2_117418601_117418800 and PGF: chr10_ 16913801_16914000 and chr10_16916401_16916600). In summary, our research comprehensively analyzed the genome-wide DNAm profiles of HP and LP Jining Grey goat ovary tissues. The data findings suggest that DNAm in goat ovaries may play an important role in determining litter size.

Decipher Score predicts prostate specific antigen persistence after prostatectomy

BACKGROUND

The aim of this study was to evaluate genomic risk of patients with persistent prostate specific antigen (PSA) using mRNA expression analysis and a validated prognostic genomic-risk classifier.

METHODS

Monocentric retrospective study including all patients who underwent radical prostatectomy (RP) by one surgeon and Decipher Test from October 2013 to December 2018. PSA persistent population was defined as all patients with two consecutive PSA>0.1 ng/mL at follow-up after the surgery. Neurovascular Structure-adjacent Frozen-section Examination (NeuroSAFE) was performed intraoperatively for research of positive surgical margins. Multivariate analysis was performed for persistent PSA (pPSA) predictors. A specific localized, organ-confined, and negative margins sub-population with PSA persistence was compared to a similar sub-population without PSA persistence for genomic differential expression analyses.

RESULTS

A total of 564 patients were included and 61 of them had pPSA. Preoperative PSA was higher in the PSA persistent group (11.6 [6.4, 21.2] vs. 6.2 [4.7, 9.2] P=0.00010), as well as PSA density (PSAd) (0.3 [0.2, 0.5] vs. 0.2 [0.1, 0.3] P=0.0001). Postoperative characteristics, Gleason Score, and positive surgical margins were significantly higher in the PSA persistent population. 31 patients had pPSA in our specific subpopulation and were compared to 217 patients with no pPSA. On multivariate analysis, only Decipher Score (OR=5.64 [1.28; 24.89], P=0.022) and preoperative PSA (OR=1.06, [1.02; 1.09], P=0.001) were significant predictors for PSA persistence. We found two genes to be significantly upregulated with a 2.5-fold change in our specific subpopulation (SERPINB11 and PDE11A).

CONCLUSIONS

We found unique genomic features of patients with pPSA, whilst confirming previous clinical findings that this condition behaves to a worse prognosis. Given this high genomic risk, further imaging studies should be performed to select patients for early treatment intensification.

Prevalence and spectrum of cancer predisposition germline mutations in young patients with the common late-onset cancers

BACKGROUND

Pathogenic germline variants (PGVs) can play a vital role in the oncogenesis process in carriers. Previous studies have recognized that PGVs contribute to early onset of tumorigenesis in certain cancer types, for example, colorectal cancer and breast cancer. However, the reported prevalence data of cancer-associated PGVs were highly inconsistent due to nonuniform patient cohorts, sequencing methods, and prominent difficulties in pathogenicity interpretation of variants. In addition to the above difficulties, due to the rarity of cases, the prevalence of cancer PGV carriers in young cancer patients affected by late-onset cancer types has not been comprehensively evaluated to date.

METHODS

A total of 131 young cancer patients (1-29 years old at diagnosis) were enrolled in this study. The patients were affected by six common late-onset cancer types, namely, lung cancer, liver cancer, colorectal cancer, gastric cancer, renal cancer, and head-neck cancer. Cancer PGVs were identified and analyzed. based on NGS-based targeted sequencing followed by bioinformatic screening and strict further evaluations of variant pathogenicity.

RESULTS

Twenty-three cancer PGVs in 21 patients were identified, resulting in an overall PGV prevalence of 16.0% across the six included cancer types, which was approximately double the prevalence reported in a previous pancancer study. Nine of the 23 PGVs are novel, thus expanding the cancer PGV spectrum. Seven of the 23 (30.4%) PGVs are potential therapeutic targets of olaparib, with potential implications for clinical manipulation. Additionally, a small prevalence of somatic mutations of some classic cancer hallmark genes in young patients, in contrast to all-age patients, was revealed.

CONCLUSION

This study demonstrates the high prevalence of PGVs in young cancer patients with the common late-onset cancers and the potentially significant clinical implications of cancer PGVs, the findings highlight the value of PGV screening in young patients across lung cancer, liver cancer, colorectal cancer, gastric cancer, renal cancer, or head-neck cancer.

Once upon a Testis: The Tale of Cyclic Nucleotide Phosphodiesterase in Testicular Cancers

Phosphodiesterases are key regulators that fine tune the intracellular levels of cyclic nucleotides, given their ability to hydrolyze cAMP and cGMP. They are critical regulators of cAMP/cGMP-mediated signaling pathways, modulating their downstream biological effects such as gene expression, cell proliferation, cell-cycle regulation but also inflammation and metabolic function. Recently, mutations in PDE genes have been identified and linked to human genetic diseases and PDEs have been demonstrated to play a potential role in predisposition to several tumors, especially in cAMP-sensitive tissues. This review summarizes the current knowledge and most relevant findings regarding the expression and regulation of PDE families in the testis focusing on PDEs role in testicular cancer development.

Functional characteristics and research trends of PDE11A in human diseases (Review)

cAMP and cGMP are important secondary messengers involved in cell regulation and metabolism driven by the G protein-coupled receptor. cAMP is converted via adenylyl cyclase (AC) and activates protein kinase A to phosphorylate intracellular proteins that mediate specific responses. cAMP signaling serves a role at multiple steps in tumorigenesis. The level of cAMP is increased in association with cancer cell formation through activation of AC-stimulatory G protein by mutation. Phosphodiesterases (PDEs) hydrolyze cAMP and cGMP to AMP and GMP. PDEs are composed of 11 families, and each can hydrolyze cAMP and cGMP or both cAMP and cGMP. PDEs perform various roles depending on their location and expression site, and are involved in several diseases, including male erectile dysfunction, pulmonary hypertension, Alzheimer's disease and schizophrenia. PDE11A is the 11th member of the PDE family and is characterized by four splice variants with varying tissue expression and N-terminal regulatory regions. Among tissues, the expression of PDE11A was highest in the prostate, and it was also expressed in hepatic skeletal muscle, pituitary, pancreas and kidney. PDE11A is the first PDE associated with an adrenocortical tumor associated genetic condition. In several studies, three PDE11A mutations have been reported in patients with Cushing syndrome with primary pigmented nodular adrenocortical disease or isolated micronodular adrenocortical disease without other genetic defects. It has been reported that an increase in PDE11A expression affects the proliferation of glioblastoma and worsens patient prognosis. The present mini-review summarizes the location of PDE11A expression, the impact of structural differences and disease relevance.

The cAMP-signaling cancers: Clinically-divergent disorders with a common central pathway

The cAMP-signaling cancers, which are defined by functionally-significant somatic mutations in one or more elements of the cAMP signaling pathway, have an unexpectedly wide range of cell origins, clinical manifestations, and potential therapeutic options. Mutations in at least 9 cAMP signaling pathway genes (TSHR, GPR101, GNAS, PDE8B, PDE11A, PRKARA1, PRKACA, PRKACB, and CREB) have been identified as driver mutations in human cancer. Although all cAMP-signaling pathway cancers are driven by mutation(s) that impinge on a single signaling pathway, the ultimate tumor phenotype reflects interactions between five critical variables: (1) the precise gene(s) that undergo mutation in each specific tumor type; (2) the effects of specific allele(s) in any given gene; (3) mutations in modifier genes (mutational "context"); (4) the tissue-specific expression of various cAMP signaling pathway elements in the tumor stem cell; and (5) and the precise biochemical regulation of the pathway components in tumor cells. These varying oncogenic mechanisms reveal novel and important targets for drug discovery. There is considerable diversity in the "druggability" of cAMP-signaling components, with some elements (GPCRs, cAMP-specific phosphodiesterases and kinases) appearing to be prime drug candidates, while other elements (transcription factors, protein-protein interactions) are currently refractory to robust drug-development efforts. Further refinement of the precise driver mutations in individual tumors will be essential for directing priorities in drug discovery efforts that target these mutations.

PDE11A gene polymorphism in testicular cancer: sperm parameters and hormonal profile

PURPOSE

Testicular germ cell tumours (TGCTs) is the most common malignancy among young adult males. The etiology is multifactorial and both environmental and genetic factors play an important role in the origin and development of TGCT. Genetic susceptibility may result from the interaction of multiple common and low-penetrance genetic variants and one of the main candidate genes is PDE11A. Many PDE11A polymorphisms were found responsible for a reduced PDE activity in TGCT patients, who often also display impaired hormone and sperm profile. The aim of this study was to investigate testicular function and PDE11A sequence in testicular cancer cases.

METHODS

Semen analysis was performed in 116 patients with unilateral and bilateral sporadic TGCTs and in 120 cancer-free controls. We also investigated hormone profile and PDE11A polymorphisms using peripheral blood samples.

RESULTS

Our data revealed that TGCT patients showed lower testosterone levels, higher gonadotropins levels and worse semen quality than controls, although the mean and the medians of sperm parameters are within the reference limits. PDE11A sequencing detected ten polymorphisms not yet associated with TGCTs before. Among these, G223A in homozygosity and A288G in heterozygosity were significantly associated with a lower risk of testicular tumour and they displayed a positive correlation with total sperm number.

CONCLUSIONS

Our findings highlight the key role of PDE11A in testis and suggest the presence of an underlying complex and fine molecular mechanism which controls testis-specific gene expression and susceptibility to testicular cancer.

Between a Rock and a Hard Place: An Epigenetic-Centric View of Testicular Germ Cell Tumors

Simple Summary

This minireview focuses on the role of epigenetics in testicular cancer. A working model is developed that postulates that epigenetic features that drive testicular cancer malignancy also enable these tumors to be cured at a high rate with chemotherapy. Chemoresistance may occur by epigenetic uncoupling of malignancy and chemosensitivity, a scenario that may be amenable to epigenetic-based therapies.

Abstract

Compared to many common solid tumors, the main genetic drivers of most testicular germ cell tumors (TGCTs) are unknown. Decades of focus on genomic alterations in TGCTs including awareness of a near universal increase in copies of chromosome 12p have failed to uncover exceptional driver genes, especially in genes that can be targeted therapeutically. Thus far, TGCT patients have missed out on the benefits of targeted therapies available to treat most other malignancies. In the past decade there has been a greater appreciation that epigenetics may play an especially prominent role in TGCT etiology, progression, and hypersensitivity to conventional chemotherapy. While genetics undoubtedly plays a role in TGCT biology, this mini-review will focus on the epigenetic “states” or features of testicular cancer, with an emphasis on DNA methylation, histone modifications, and miRNAs associated with TGCT susceptibility, initiation, progression, and response to chemotherapy. In addition, we comment on the current status of epigenetic-based therapy and epigenetic biomarker development for TGCTs. Finally, we suggest a unifying “rock and a hard place” or “differentiate or die” model where the tumorigenicity and curability of TGCTs are both dependent on common but still ill-defined epigenetic states.

Molecular Genetic and Genomic Alterations in Cushing's Syndrome and Primary Aldosteronism

The genetic alterations that cause the development of glucocorticoid and/or mineralocorticoid producing benign adrenocortical tumors and hyperplasias have largely been elucidated over the past two decades through advances in genomics. In benign aldosterone-producing adrenocortical tumors and hyperplasias, alteration of intracellular calcium signaling has been found to be significant in aldosterone hypersecretion, with causative defects including those in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2. In benign cortisol-producing adrenocortical tumors and hyperplasias abnormal cyclic adenosine monophosphate-protein kinase A signaling has been found to play a central role in tumorigenesis, with pathogenic variants in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B being implicated. The role of this signaling pathway in the development of Cushing's syndrome and adrenocortical tumors was initially discovered through the study of the underlying genetic defects causing the rare multiple endocrine neoplasia syndromes McCune-Albright syndrome and Carney complex with subsequent identification of defects in genes affecting the cyclic adenosine monophosphate-protein kinase A pathway in sporadic tumors. Additionally, germline pathogenic variants in ARMC5, a putative tumor suppressor, were found to be a cause of cortisol-producing primary bilateral macronodular adrenal hyperplasia. This review describes the genetic causes of benign cortisol- and aldosterone-producing adrenocortical tumors.

A phosphodiesterase 11 (Pde11a) knockout mouse expressed functional but reduced Pde11a: Phenotype and impact on adrenocortical function

Phosphodiesterases catalyze the hydrolysis of cyclic nucleotides and maintain physiologic levels of intracellular concentrations of cyclic adenosine and guanosine mono-phosphate (cAMP and cGMP, respectively). Increased cAMP signaling has been associated with adrenocortical tumors and Cushing syndrome. Genetic defects in phosphodiesterase 11A (PDE11A) may lead to increased cAMP signaling and have been found to predispose to the development of adrenocortical, prostate, and testicular tumors. A previously reported Pde11a knockout (Pde11a-/-) mouse line was studied and found to express PDE11A mRNA and protein still, albeit at reduced levels; functional studies in various tissues showed increased cAMP levels and reduced PDE11A activity. Since patients with PDE11A defects and Cushing syndrome have PDE11A haploinsufficiency, it was particularly pertinent to study this hypomorphic mouse line. Indeed, Pde11a-/- mice failed to suppress corticosterone secretion in response to low dose dexamethasone, and in addition exhibited adrenal subcapsular hyperplasia with predominant fetal-like features in the inner adrenal cortex, mimicking other mouse models of increased cAMP signaling in the adrenal cortex. We conclude that a previously reported Pde11a-/- mouse showed continuing expression and function of PDE11A in most tissues. Nevertheless, Pde11a partial inactivation in mice led to an adrenocortical phenotype that was consistent with what we see in patients with PDE11A haploinsufficiency.

Phenotypic and genotypic features of a large kindred with a germline AIP variant

CONTEXT

Acromegaly is usually a sporadic disease, but familial cases occur. Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are associated with familial pituitary adenoma predisposition. However, the pathogenicity of some AIP variants remains unclear and additional unknown genes may be involved.

OBJECTIVE

To explore the phenotype and genotype of a large kindred carrying the p.R304Q AIP variant.

METHODS

The family comprised 52 family members at risk of carrying the p.R304Q AIP variant including a case with gigantism and one with acromegaly and several family members with acromegalic features. Nine family members (three trios) underwent exome sequencing to identify putative pathogenic variants.

RESULTS

We identified 31 p.R304Q carriers, and based on two cases with somatotropinomas, the disease penetrance was 6%. We observed physical signs of acromegaly in several family members, which were independent of AIP status. Serum insulin-like growth factor-I (IGF-I) levels in all family members were above the mean for age and sex (IGF-I SDS: +0.6 [CI95% +0.4-0.9], P < .01). Exome analysis identified two candidate genes: PDE11A, known to be associated with the development of adrenal tumours, and ALG14. Ten asymptomatic p.R304Q family members (age >50 years) were screened for the PDE11A and ALG14 variant; both variants were present in five of ten persons.

CONCLUSIONS

This large family adds new information on the p.R304Q AIP variant, and data suggest two new candidate genes could be associated with growth hormone excess.

Adrenocortical tumorigenesis: Lessons from genetics

Advances in genomics over the past two decades have allowed for elucidation of the genetic alterations leading to the development of adrenocortical tumors and/or hyperplasias. These molecular changes were initially discovered through the study of rare familial tumor syndromes such as McCune-Albright Syndrome, Carney complex, Li-Fraumeni syndrome, and Beckwith-Wiedemann syndrome, with the identification of alterations in genes and molecular pathways that subsequently led to the discovery of aberrations in these or related genes and pathways in sporadic tumors. Genetic alterations in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B, that lead to aberrant cyclic adenosine monophosphate-protein (cAMP) kinase A signaling, were found to play a major role in the development of benign cortisol-producing adrenocortical tumors and/or hyperplasias, whereas genetic defects in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2 were implicated in the development of benign aldosterone-producing tumors and/or hyperplasias through modification of intracellular calcium signaling. Germline ARMC5 defects were found to cause the development of primary bilateral macronodular adrenocortical hyperplasia with glucocorticoid and/or mineralocorticoid oversecretion. Adrenocortical carcinoma was linked primarily to aberrant p53 signaling and/or Wnt-β-catenin signaling, as well as IGF2 overexpression, with frequent genetic alterations in TP53, ZNRF3, CTNNB1, and 11p15. This review focuses on the genetic underpinnings of benign cortisol- and aldosterone-producing adrenocortical tumors/hyperplasias and adrenocortical carcinoma.

Genetics of testicular germ cell tumors

PURPOSE OF REVIEW

Understanding the molecular basis underlying testicular germ cell tumors (TGCTs) may help improve patient outcomes, particularly for patients with poorer risk or chemoresistant disease. Here, we review the major contemporary advances in elucidating TGCT genetics by discussing patterns of TGCT inheritance, recent genomic and transcriptomic discoveries in TGCT, and the role of genetics in predicting therapeutic resistance and in guiding treatment.

RECENT FINDINGS

In the absence of a major high-penetrance TGCT susceptibility gene, inheritance is likely driven by a complex polygenic model with considerable variation. The most common genomic alterations found in TGCTs include gains in chromosome 12p and mutations in KIT, KRAS, and NRAS, particularly in seminomas. Sensitivity to cisplatin-based chemotherapy likely relies on intact TP53, reciprocal loss of heterozygosity, and high mitochondrial priming. Targetable mutations are uncommon in TGCTs, however, posing a challenge for the development of effective personalized therapies. Consistent with the characteristically low tumor mutational burden, immune checkpoint inhibitors do not appear to be effective for most TGCTs.

SUMMARY

Refinements in next-generation sequencing techniques over the last few years have enabled considerable advances in elucidating the genomic, transcriptomic, and epigenetic landscape of TGCTs. Future efforts focused on developing novel treatment modalities are needed.

Latin American Study of Hereditary Breast and Ovarian Cancer LACAM: A Genomic Epidemiology Approach

Purpose: Hereditary Breast and Ovarian Cancer (HBOC) syndrome is responsible for ~5-10% of all diagnosed breast and ovarian cancers. Breast cancer is the most common malignancy and the leading cause of cancer-related mortality among women in Latin America (LA). The main objective of this study was to develop a comprehensive understanding of the genomic epidemiology of HBOC throughout the establishment of The Latin American consortium for HBOC-LACAM, consisting of specialists from 5 countries in LA and the description of the genomic results from the first phase of the study. Methods: We have recruited 403 individuals that fulfilled the criteria for HBOC from 11 health institutions of Argentina, Colombia, Guatemala, Mexico and Peru. A pilot cohort of 222 individuals was analyzed by NGS gene panels. One hundred forty-three genes were selected on the basis of their putative role in susceptibility to different hereditary cancers. Libraries were sequenced in MiSeq (Illumina, Inc.) and PGM (Ion Torrent-Thermo Fisher Scientific) platforms. Results: The overall prevalence of pathogenic variants was 17% (38/222); the distribution spanned 14 genes and varied by country. The highest relative prevalence of pathogenic variants was found in patients from Argentina (25%, 14/57), followed by Mexico (18%, 12/68), Guatemala (16%, 3/19), and Colombia (13%, 10/78). Pathogenic variants were found in BRCA1 (20%) and BRCA2 (29%) genes. Pathogenic variants were found in other 12 genes, including high and moderate risk genes such as MSH2, MSH6, MUTYH, and PALB2. Additional pathogenic variants were found in HBOC unrelated genes such as DCLRE1C, WRN, PDE11A, and PDGFB. Conclusion: In this first phase of the project, we recruited 403 individuals and evaluated the germline genetic alterations in an initial cohort of 222 patients among 4 countries. Our data show for the first time in LA the distribution of pathogenic variants in a broad set of cancer susceptibility genes in HBOC. Even though we used extended gene panels, there was still a high proportion of patients without any detectable pathogenic variant, which emphasizes the larger, unexplored genetic nature of the disease in these populations.

An epigenomic approach to identifying differential overlapping and cis-acting lncRNAs in cisplatin-resistant cancer cells

Long noncoding RNAs (lncRNAs) are critical regulators of cell biology whose alteration can lead to the development of diseases such as cancer. The potential role of lncRNAs and their epigenetic regulation in response to platinum treatment are largely unknown. We analyzed four paired cisplatin-sensitive/resistant non-small cell lung cancer and ovarian cancer cell lines. The epigenetic landscape of overlapping and cis-acting lncRNAs was determined by combining human microarray data on 30,586 lncRNAs and 20,109 protein coding mRNAs with whole-genome bisulfite sequencing. Selected candidate lncRNAs were further characterized by PCR, gene-ontology analysis, and targeted bisulfite sequencing. Differential expression in response to therapy was observed more frequently in cis-acting than in overlapping lncRNAs (78% vs. 22%, fold change ≥1.5), while significantly altered methylation profiles were more commonly associated with overlapping lncRNAs (29% vs. 8%; P value <0.001). Moreover, overlapping lncRNAs contain more CpG islands (CGIs) (25% vs. 17%) and the majority of CGI-containing overlapping lncRNAs share these CGIs with their associated coding genes (84%). The differences in expression between sensitive and resistant cell lines were replicated in 87% of the selected candidates (P<0.05), while our bioinformatics approach identifying differential methylation was confirmed in all of the selected lncRNAs (100%). Five lncRNAs under epigenetic regulation appear to be involved in cisplatin resistance (AC091814.2, AC141928.1, RP11-65J3.1-002, BX641110, and AF198444). These novel findings provide new insights into epigenetic mechanisms and acquired resistance to cisplatin that highlight specific lncRNAs, some with unknown function, that may signal strategies in epigenetic therapies.

Autozygosity reveals recessive mutations and novel mechanisms in dominant genes: implications in variant interpretation

PURPOSE

The purpose of this study is to describe recessive alleles in strictly dominant genes. Identifying recessive mutations in genes for which only dominant disease or risk alleles have been reported can expand our understanding of the medical relevance of these genes both phenotypically and mechanistically. The Saudi population is enriched for autozygosity, which enhances the homozygous occurrence of alleles, including pathogenic alleles in genes that have been associated only with a dominant inheritance pattern.

METHODS

Exome sequencing of patients from consanguineous families with likely recessive phenotypes was performed. In one family, the genotype of the deceased children was inferred from their parents due to lack of available samples.

RESULTS

We describe the identification of 11 recessive variants (5 of which are reported here for the first time) in 11 genes for which only dominant disease or risk alleles have been reported. The observed phenotypes for these recessive variants were novel (e.g., FBN2-related myopathy and CSF1R-related brain malformation and osteopetrosis), typical (e.g., ACTG2-related visceral myopathy), or an apparently healthy state (e.g., PDE11A), consistent with the corresponding mouse knockout phenotypes.

CONCLUSION

Our results show that, in the era of genomic sequencing and "reverse phenotyping," recessive variants in dominant genes should not be dismissed based on perceived "incompatibility" with the patient's phenotype before careful consideration.Genet Med advance online publication 06 April 2017.

Testicular germ cell tumours

Testicular germ cell tumours are at the crossroads of developmental and neoplastic processes. Their cause has not been fully elucidated but differences in incidences suggest that a combination of genetic and environment factors are involved, with environmental factors predominating early in life. Substantial progress has been made in understanding genetic susceptibility in the past 5 years on the basis of the results of large genome-wide association studies. Testicular germ cell tumours are highly sensitive to radiotherapy and chemotherapy and hence have among the best outcomes of all tumours. Because the tumours occur mainly in young men, preservation of reproductive function, quality of life after treatment, and late effects are crucial concerns. In this Seminar, we provide an overview of advances in the understanding of the epidemiology, genetics, and biology of testicular germ cell tumours. We also summarise the consensus on how to treat testicular germ cell tumours and focus on a few controversies and improvements in the understanding of late effects of treatment and quality of life for survivors.