Male Germ Cell Tumors Research Articles

The effect of chemotherapy regimens in male germ cell tumors on the development of primary hypogonadism

Male germ cell tumors (GCT) have excellent survival. Long-term sequelae in cancer survivors are an evolving field. We evaluated the risk of patients with GCT to develop primary hypogonadism and adherence to guideline-recommended therapy in a real-world cohort. Monocentric study at a tertiary cancer centre to evaluate treated GCT-patients (2001–2019). Post therapeutic male endocrine function, International Index of Erectile Function (IIEF)-5 and The aging males’ symptoms rating scale (AMS) questionnaires were assessed. The overall response rates were low, with 44 of 402 contacted patients participating in the study. From these, 32(73%) underwent blood analysis, 42(95%) answered the IIEF-5 and 43(98%) the AMS. Latent hypogonadism (serum testosterone 8–12 nmol/l) was found in n = 9 (28%) and manifest hypogonadism (testosterone < 8 nmol/l) in n = 8 (25%). 50% (n = 21) indicated erectile dysfunction on IIEF-5 (cut off ≤ 21 pts.) and 62.8% (n = 27) reported symptomatic affection on AMS (cut off ≥ 27 pts.). Majority of tested patients revealed different degrees of hypogonadism. Standard instruments were able to detect gonadal damage in > 50%, which underscored the clinical need to evaluate endocrine function in cancer survivors. We further indicated the difficulties of today’s research and provided starting points to assess barriers for study participations.

Descriptive analysis of brain metastases (BM) of solid neoplasms in an academic hospital from a low- and middle-income country (LMIC) with a Hispanic population.

e14015 Background: Multidisciplinary management of BM of solid cancers integrates different combinations of treatment modalities. The scarcity of SRS centers has prevented widespread adoption of this therapy for appropriately selected patients. Methods: One-hundred eighteen (51.7% female, 48.3% male, median age 59 years) BM patients from a National Health Institute from Mexico (INCMNSZ) were included and analyzed. Results: The most common primary tumors were lung and breast cancers (25 cases each, representing 21% of the whole cohort), kidney cancer (14%), male germ cell tumors (10%), metastatic carcinoma of unknown primary (CUP) (5%), upper- and lower- gastrointestinal cancers (5%), thyroid differentiated cancers (5%), followed by melanoma, prostate, ovarian, hepatobiliary cancers and sarcoma (3% each of them) and urothelial carcinoma (2%) being the least common. No biopsy was reported for only one case. The most common histomolecular tumors were adenocarcinoma of the lung (17 cases), renal cell carcinoma (17), triple negative (TN) breast cancer (BC) (9), HER-2+ BC (7), Nonseminomatous germ cell tumor (7), CUP (6), ER+/HER-2+ BC (5), Germ cell tumor with choriocarcinoma (5), small-cell lung cancer (SCLC) (5), melanoma (5), prostate adenocarcinoma (5), thyroid differentiated cancer not otherwise specified (NOS) (5). Rectal adenocarcinoma, high-grade serous ovarian cancer, ER+/PR+ BC, sarcomas and NSCLC (3 cases, each) and urothelial carcinoma (2). Rare tumor subtypes, with one case, each included hepatocellular carcinoma, PR+/HER2+ BC, follicular thyroid cancer, esophageal, gastric and colonic adenocarcinomas, neuroendocrine prostate, neuroendocrine gallbladder, endometrial, large cell neuroendocrine lung carcinomas and cholangiocarcinoma. A solitary BM was present in 44 patients (37.3%), 2-3 BM in 30 (25.4%) and &gt;3 BM in 44 patients (37.3%). 18 patients (15.2%) were not symptomatic at the time of diagnosis. 79 patients were treated with Whole-Brain Radiotherapy (WBRT), ten with a combination of surgery and adjuvant WBRT, seven with surgical resection without radiotherapy, only five included SRS as part of their treatment and seventeen received only supportive care. There was no difference in overall survival (OS) between treatment modalities excluding supportive care (p=0.05). Conclusions: Our experience from a LMIC with Hispanic population highlights that more than 50% of BM metastasize from solid tumors different from lung and breast cancers. Even though SRS has been included in recent guidelines from ASCO and ESMO, WBRT is the option most commonly included in multimodality treatments.

P188 - Influence of prognostic group classification of advanced male germ cell tumor on treatment outcomes

P188 - Influence of prognostic group classification of advanced male germ cell tumor on treatment outcomes

UP56 - Influence of prognostic group classification of advanced male germ cell tumor on treatment outcomes

UP56 - Influence of prognostic group classification of advanced male germ cell tumor on treatment outcomes

Molecular correlates of male germ cell tumors with overgrowth of components resembling somatic malignancies

A small subset of male germ cell tumors (GCT) demonstrates overgrowth of histologic components that resemble somatic malignancies (e.g., sarcoma, carcinoma). The presence of so-called “somatic-type” malignancies (SM) in GCT has been associated with chemotherapy-resistance and poor clinical outcomes in prior studies. However, the molecular characteristics of these tumors remain largely undescribed. In this study, we performed a multi-platform molecular analysis of GCTs with SM diagnosed in 36 male patients (primary site: testis, 29 and mediastinum, 7). The most common histologic types of SM were sarcoma and embryonic-type neuroectodermal tumor (ENT, formerly known as “PNET”), present in 61% and 31% of cases, respectively. KRAS and TP53 mutations were identified by DNA sequencing in 28% of cases each, with enrichment of TP53 mutations in mediastinal tumors (86%). Gains in the short arm of chromosome 12 were seen in 91% of cases, likely reflecting the presence of isochromosome 12p. Numerous copy number changes indicative of widespread aneuploidy were found in 94% of cases. Focal homozygous deletions and amplifications were also detected, including MDM2 amplifications in 16% of cases. Sequencing of paired samples in 8 patients revealed similar mutational and copy number profiles in the conventional GCT and SM components. Oncogenic gene fusions were not detected using RNA sequencing of SM components from 9 cases. DNA methylation analysis highlighted the distinct methylation profile of SM components that sets them apart from conventional GCT components. In conclusion, GCT with SM are characterized by widespread aneuploidy, a distinct epigenetic signature and the presence of mutations that are otherwise rare in testicular GCT without SM. The similarity of the mutational and DNA methylation profiles of different histologic types of SM suggests that the identification of SM components could be more important than their precise histologic subclassification, pending confirmation by further studies.

The anticancer effects of Metformin in the male germ tumor SEM-1 cell line are mediated by HMGA1.

Germ cell tumors (GCTs) are the most common type of cancer in young men. These tumors usually originate from the testis, but they can occasionally develop from extragonadal sites probably due to primordial germ cells (PGCs) migration errors. Cisplatin-based chemotherapy is usually effective for male GCTs, but the risk of toxicity is high and new therapeutic strategies are needed. Although Metformin (Met) has been widely studied as a potential cancer treatment over the past decades, there is limited evidence to support its use in treating male GCTs. Additionally, the mechanism by which it acts on tumor cells is still not entirely understood. SEM-1 cells, a newly established human cell line of extragonadal origin, were treated with Met. Cell viability was studied by MTT assay, while cell migration and invasion were studied by the wound healing assay and the transwell assay, respectively. The effect of Met on 3D spheroid formation was determined by seeding SEM-1 cells in appropriate cell suspension culture conditions, and cell cycle was characterized by flow cytometry. Factors involved in PGCs migration and GCT invasion, such as IGFBP1, IGF1R, MMP-11 and c-Kit, together with cyclin D1 (a key regulator of cell cycle progression), and the upstream factor, HMGA1, were determined by immunoblots. Treatment of SEM-1 cells with Met resulted in a potent and dose-dependent reduction of cell proliferation, as evidenced by decreased nuclear abundance of cyclin D1 and cell cycle arrest in G1 phase. Also, Met prevented the formation of 3D spheroids, and blocked cell migration and invasion by reducing the expression of IGFBP1, IGF1R and MMP-11. Both, IGFBP1 and MMP-11 are under control of HMGA1, a chromatin-associated protein that is involved in the regulation of important oncogenic, metabolic and embryological processes. Intriguingly, an early reduction in the nuclear abundance of HMGA1 occurred in SEM-1 cells treated with Met. Our results document the antiproliferative and antimigratory effects of Met in SEM-1 cells, providing new insights into the potential treatments for male GCTs. The anticancer properties of Met in SEM-1 cells are likely related to its ability to interfere with HMGA1 and downstream targets, including cyclin D1, the IGFs system, and MMP-11.

Age-incidence patterns of seminoma and nonseminoma among males and females in Germany and the United States, 2008-2016.

The comparison of the incidence of gonadal germ cell tumors among males and females can provide insights that cannot be gained by separately studying these tumors. Incidence data on male and female gonadal germ cell tumors were drawn from the cancer registries of North Rhine-Westphalia, Germany, and the United States Surveillance, Epidemiology and End Results program, for non-Hispanic White persons only, for the years 2008-2016. We estimated age-standardized and age-, and histology-specific incidence rates. We included 21,840 male and 716 female gonadal germ cell tumors. Incidence rates among males were higher in Germany (95.8 per million, standard error [SE] 1.1) than in the United States (68.0, SE 0.6), while incidence rates among females were lower in Germany (1.9, SE 0.2) than in the United States (2.6, SE 0.1). The characteristic peak of infantile (age 0-4 years) germ cell tumors among males were missing among females. The age peak of ovarian germ cell tumors occurred 15-20 years earlier (Germany: 10-14 years, United States: 15-19years) than the age peak of testicular germ cell tumors (30-34years). The three most common testicular germ cell tumors histologies were seminoma, mixed germ cell tumors, and embryonal carcinoma Among females, the three most common ovarian germ cell tumors histologies were teratoma, yolk sac tumor, monodermal teratomas, and somatic-type tumors arising from dermoid cysts in both countries. The characteristic peak of infantile (age 0-4 years) germ cell tumors among males was missing among females. The shapes of the age-specific incidence curves are similar for males and females in Germany and the United States, though with much lower incidence rates in females, suggesting a common pathogenesis. The lower rates among females may be due to the lower number of initiated tumors in the absence of the Y-chromosome, and the earlier peak among females may be due to a younger age at puberty.

Analytical Validation and Performance Characteristics of Molecular Serum Biomarkers, miR-371a-3p and miR-372-3p, for Male Germ Cell Tumors, in a Clinical Laboratory Setting

Detection of serum embryonic miRNAs miR-371a-3p and miR-372-3p has been proposed to aid in diagnosis, prognosis, and management of patients with testicular germ cell tumors (GCTs). This study describes the analytical validation and performance of a laboratory-developed test to detect these miRNA targets by stem loop real-time quantitative RT-PCR (RT-qPCR) in serum from patients with GCTs. The assay was standardized using an exogenous spike-in control of nonhuman miRNA from Caenorhabditis elegans (cel-miR-39-3p) to assess extraction efficiency, and an endogenous housekeeping miRNA, miR-30b-5p, to control for miRNA normalization. miRNA results were expressed as relative expression level, using the comparative threshold cycle method (2ΔΔCT). Analytical sensitivity of miR-371a-3p and miR-372-3p was 12.5 and 1.25 copies/μL, respectively. Clinical accuracy was evaluated using GCT patients with (n=34) and without (n=17) active disease. Positive/negative cutoffs and indeterminate findings were established on the basis of results from healthy volunteers (n=25) and assay precision. miR-371a-3p and miR-372-3p exhibited a sensitivity of 81.8% and 87.5%, respectively, and a specificity of 100% and 94%, respectively, and an area under the receiver operating characteristic curve of 0.93 and 0.95, respectively. Taken together, RT-qPCR testing for serum miR-371a-3p and miR-372-3p represents a robust, sensitive, and specific clinical assay to aid in the clinical management of patients with GCT.

Sex chromosome DSD individuals with mosaic 45,X0 and aberrant Y chromosomes in 46,XY cells: distinct gender phenotypes and germ cell tumour risks§

“Differences of Sexual Development (DSD),” individuals with rearranged Y chromosome breaks in their 46,XY cells are reported with male and female gender phenotypes and differences in germ cell tumour (GCT) risk. This raised the question of whether male or female gender and GCT risk depends on the site of the break and/or rearrangement of the individual´s Y chromosome. In this paper, we report molecular mapping of the breakpoint on the aberrant Y chromosome of 22 DSD individuals with a 45,X/46,XY karyotype reared with a different gender. Their Y chromosome breaks are found at different sites on the long and short Y arms. Our data indicate that gender rearing is, neither dependent on the site of Y breakage, nor on the amount of 45,X0 cells in the individuals' leukocytes. Most prominent are secondary rearrangements of the Y chromosome breaks forming di-centric Y-structures (“dic-Y”). Duplications of the short Y arm and the proximal part of the long Y arm are the results. A putative GCT risk has been analysed with immunohistochemical experiments on some dysgenetic gonadal tissue sections. With specific antibodies for OCT3/4 expression, we marked the pluripotent germ cell fraction being potential tumour precursor cells. With specific antibodies for DDX3Y, TSPY, and UTY we analyzed their putative Gonadoblastoma Y (GBY) tumour susceptibility function in the same specimen. We conclude GBY expression is only diagnostic for GCT development in the aberrant germ cells of these DSD individuals when strong OCT3/4 expression has marked their pluripotency.

Chromosome 3p25.3 Gain Is Associated With Cisplatin Resistance and Is an Independent Predictor of Poor Outcome in Male Malignant Germ Cell Tumors.

PURPOSECisplatin is the main systemic treatment modality for male type II germ cell tumors (GCTs). Although generally very effective, 5%-10% of patients suffer from cisplatin-resistant disease. Identification of the driving mechanisms of resistance will enable improved risk stratification and development of alternative treatments.METHODSWe developed and characterized cisplatin-resistant GCT cell line models and compared their molecular characteristics with patient samples with cisplatin resistance and/or a poor clinical outcome. Subsequently, the association between the overlapping genetic features and clinical data was assessed. Finally, we used Cox regression to determine the prognostic relevance of these features within the currently used risk classification.RESULTSGain of chromosome 3p25.3 was detected in all cisplatin-resistant cell lines, and copy number of this region correlated with the level of resistance (R = 0.96, P = 1.5e-04). Gain of this region was detected at low frequencies in primary tumors and at higher frequencies in relapsed and/or cisplatin-resistant tumors. Chromosome 3p25.3 gain was associated with shorter progression-free survival and overall survival, with the strongest association observed in nonseminomas excluding pure teratomas. 3p25.3 gain was more frequently observed in tumors with yolk sac tumor histology and predicted adverse outcome independent of the International Germ Cell Cancer Collaborative Group risk classification and the presence of TP53/MDM2 alterations.CONCLUSIONOn the basis of both in vitro analyses and clinical data, we found 3p25.3 to be strongly associated with cisplatin resistance and poor clinical outcome in male type II GCTs. Using genomic profiling, 3p25.3 status could help to improve risk stratification in male patients with type II GCT. Further characterization of this locus and underlying mechanisms of resistance is warranted to guide development of novel treatment approaches for cisplatin-resistant disease.

Peritoneal carcinosis in male germ cell tumor patients: a registry study compiled by the German Testicular Cancer Study Group (GTCSG)

PurposeTo report on the clinical characteristics, outcome, and frequency of peritoneal carcinosis (PC) in patients with advanced germ cell tumors (GCT), a multicenter registry analysis was carried out.MethodsA multicenter registry analysis was conducted by the German Testicular Cancer Study Group (GTCSG) with international collaborators. Data was collected and analyzed retrospectively. Patients were eligible for inclusion if PC was diagnosed either by radiologic or histopathologic finding during the course of disease. Descriptive and explorative statistical analysis was carried out with cancer-specific survival (CSS) as primary study endpoint.ResultsCollaborators from ten GCT expert centers identified 28 GCT (0.77%) patients with PC after screening approximately 3767 GCT patient files and one case was contributed from a cancer registry request. Patients were diagnosed from 1997 to 2019 at a median age of 37 years (interquartile range, 13). Two patients (7%) presented with stage I and 27 patients (93%) with synchronous metastatic disease at first diagnosis. The primary histology was seminoma in seven (27%) and non-seminoma in 21 patients (72%). PC was detected after a median of 15.3 months from primary diagnosis (range 0–177) and two consecutive treatment lines (range 0–5), respectively. The median CSS from the time of detection of PC was 10.5 months (95%Confidence Interval 0.47–1.30) associated with an overall 2-year CSS rate of 30%.ConclusionPC represents a rare tumor manifestation in GCT patients and was primarily associated with the occurrence of advanced cisplatin-refractory disease conferring to a dismal prognosis.

Influence of Prognostic Group Classification of Advanced Male Germ Cell Tumor on Treatment Outcomes

Background: Male germ cell tumor is a rare disease, associated with high rates of cure, including in the advanced setting. This disease mostly affects young males aged 15-34 years. The rising incidence trends of germ cell tumors in the last two decades have defined a new priority area of oncology. Objective: To investigate the influence of prognostic group classification and histology on treatment outcomes in men treated in a single institution in Pakistan. Methods: We developed an observational study on fifty male patients diagnosed with advanced germ cell cancer completing first-line treatment, between 2011-2014. Patients with a follow-up time of at least 5 years post-treatment were included. Patients were classified into good, intermediate, and poor prognostic groups, according to the International Germ Cell Cancer Collaborative Group classification (IGCCCG). The outcomes of all three prognostic groups were measured including response to first-line treatment according to Memorial Sloan-Kettering Cancer Center criteria and five years OS. Survival rates were calculated using Kaplan and Meier method. The level of significance was set at P &lt; 0.05. Results: Overall 50 patients were included in the study. The mean age of patients was 30.6 years + 9.49 years. The most common primary site of involvement was the right testicle i.e.56.0%. Complete responses (CR) were observed in 23 (46.0%) patients. The patients classified into the good prognostic group (n=29) had significantly superior (p=0.002) five years OS (86.2%, n= 25) than intermediate and poor groups. Additionally, CR was higher for seminoma-type cancer i.e. 12 (63.15%) while it was limited to 11(35.48%) in non-seminoma; however, the inferior response rate in NSGCT did not translate into statistical significance in 5 years OS. Conclusion: The IGCCCG prognostic grouping system is an effective tool for predicting treatment outcomes in terms of 5-year overall survival in our local population based in a low-middle income setting.

The glucose-sensing transcription factor MLX balances metabolism and stress to suppress apoptosis and maintain spermatogenesis.

Male germ cell (GC) production is a metabolically driven and apoptosis-prone process. Here, we show that the glucose-sensing transcription factor (TF) MAX-Like protein X (MLX) and its binding partner MondoA are both required for male fertility in the mouse, as well as survival of human tumor cells derived from the male germ line. Loss of Mlx results in altered metabolism as well as activation of multiple stress pathways and GC apoptosis in the testes. This is concomitant with dysregulation of the expression of male-specific GC transcripts and proteins. Our genomic and functional analyses identify loci directly bound by MLX involved in these processes, including metabolic targets, obligate components of male-specific GC development, and apoptotic effectors. These in vivo and in vitro studies implicate MLX and other members of the proximal MYC network, such as MNT, in regulation of metabolism and differentiation, as well as in suppression of intrinsic and extrinsic death signaling pathways in both spermatogenesis and male germ cell tumors (MGCTs).

Case Report: Rare Presentation of Mixed Germ Cell Tumor in an Infant

The estimated incidence of pediatric testis tumor is 0.5–2.0 per 100,000 children, accounting for 1–2% of all pediatric tumors. Mixed germ cell tumors (MGCT) in prepubertal males are exceedingly rare, with only one previous case report found in the literature. We report a case of a MGCT in an infant. For prepubertal males, GCTs typically present with a painless scrotal mass, though trauma, testis torsion and hydrocele are also common presentations. Similar to such tumors in postpubertal males, ultrasonography, computed tomography, and tumor markers are integral to determine the best treatment. The patient described in this report presented with a painless scrotal mass. Following orchiectomy, the patient was found to have MGCT that was limited to the testis. With prudent management, these patients tend to have favorable prognoses.

Nonepithelial ovarian cancers

Key content Nonepithelial ovarian cancers (NEOCs) are rare forms of ovarian cancer, including malignant ovarian germ cell tumours (MOGCTs), sex cord‐stromal tumours (SCSTs) and ovarian sarcoma. Tumour markers including alpha‐fetoprotein, human chorionic gonadotrophin, lactate dehydrogenase and inhibin can be useful in aiding preoperative diagnosis of malignant ovarian masses. NEOCs are staged using a similar classification to epithelial ovarian tumours; however, the staging system for male germ cell tumours is considered a more useful prognostic tool. These tumours can occur at any age; however, many present in the reproductive years, and fertility‐sparing treatments are often required. Advanced‐stage MOGCTs and SCSTs are managed with debulking surgery and platinum‐based adjuvant chemotherapy, with the regimen of bleomycin, etoposide and cisplatin being most widely used. Learning objectives To understand the classification and pathology of NEOCs. To describe the role of tumour markers in diagnostic criteria and to be aware of the FIGO staging classifications and their prognostic use. To understand management protocols and follow‐up regimens. Ethical issues Patients of reproductive age risk infertility if preoperative diagnosis is incorrect and more extensive surgery involving bilateral salpingo‐oophorectomy is performed.

Effect of pretreatment central adiposity on the cardiometabolic risk of male germ cell tumor survivors after cisplatin-based chemotherapy.

5019 Background: Preferential fat accumulation in the visceral compartment (i.e. central adiposity) increases cardiovascular risk in the general population independent of body mass index (BMI). We investigated how body fat distribution modulates the cardiometabolic risk of male germ cell tumor (GCT) survivors after cisplatin-based chemotherapy. Methods: For 456 patients in The Platinum Study enrolled at Memorial Sloan Kettering Cancer Center, visceral (VAT) and subcutaneous (SAT) adipose tissue compartments were quantified on pre-chemotherapy computed tomography (CT) scans (median time between CT and chemotherapy: 13 days, range: 0-56). The VAT/SAT ratio was calculated as a quantitative indicator of central adiposity. Endpoints were (I) post-chemotherapy cardiovascular risk as per the office-based Framingham risk calculator, and (II) incidence of post-chemotherapy cardiometabolic disease defined as need for new anti-hypertensive drugs, or lipid-lowering drugs, or medication used to treat diabetes. Changes in fat distribution after chemotherapy were analyzed in a subgroup with post-chemotherapy CTs (n = 108; median interval from chemotherapy start: 18 months, range: 7-185). Linear regression with interaction terms (endpoint 1, subgroup analysis) and Cox proportional hazard regression (endpoint 2) were applied. Results: For all 456 patients, median age at chemotherapy initiation was 31 years and median follow-up was 27 months (range: 7, 207). At baseline (pre-chemotherapy), the median BMI was 26.2 kg/m2, and 102 patients (22.4%) had a BMI of ≥30 kg/m2. The median VAT/SAT ratio at baseline CT was 0.49, and positively associated with higher post-chemotherapy Framingham risk scores after adjustment for age, BMI, and blood pressure measurements at chemotherapy start, as well as post-therapy follow-up time (adjusted β-estimate: 1.36, 95% CI: 1.15, 1.59, p &lt; 0.001). A higher VAT/SAT ratio also inferred a higher likelihood of new onset cardiometabolic disease in patients with BMI ≥30 kg/m2 (age-adjusted HR: 3.11, 95%CI: 1.01, 9.62, p = 0.048), but not in those with BMI &lt; 30 kg/m2. In the subgroup analysis, we observed a significant increase of BMI after chemotherapy (mean: +1.1 kg/m2, 95% CI: +0.58, +1.54; p &lt; 0.001). Changes in BMI were positively associated with changes of the VAT/SAT ratio (β-estimate: 3.0, 95% CI: 2.23, 4.04; p &lt; 0.001), meaning that weight gain occurred preferentially in the VAT compartment, while weight loss tended to be paralleled by an improved body fat distribution. Conclusions: In male GCT patients, central adiposity at baseline increases cardiometabolic risk after cisplatin-based chemotherapy, particularly for obese individuals. Quantification of an individual’s body fat distribution on pre-chemotherapy CT could potentially help to identify high risk individuals who may benefit from intensified risk-modulating interventions.

Molecular Biology of Pediatric and Adult Male Germ Cell Tumors.

Simple SummaryAlthough testicular germ cell tumors (TGCTs) are rare pediatric malignancies, they are the most common malignancies in young adult men. The similarities and differences between TGCTs in adults and children, taking into account the clinic presentation, biology, and molecular changes, are underexplored. In this paper, we aim to provide an overview of the molecular aspects of TGCTs, drawing a parallel between the findings in adult and pediatric groups.Cancer is a leading cause of death by disease in children and the second most prevalent of all causes in adults. Testicular germ cell tumors (TGCTs) make up 0.5% of pediatric malignancies, 14% of adolescent malignancies, and are the most common of malignancies in young adult men. Although the biology and clinical presentation of adult TGCTs share a significant overlap with those of the pediatric group, molecular evidence suggests that TGCTs in young children likely represent a distinct group compared to older adolescents and adults. The rarity of this cancer among pediatric ages is consistent with our current understanding, and few studies have analyzed and compared the molecular basis in childhood and adult cancers. Here, we review the major similarities and differences in cancer genetics, cytogenetics, epigenetics, and chemotherapy resistance between pediatric and adult TGCTs. Understanding the biological and molecular processes underlying TGCTs may help improve patient outcomes, and fuel further investigation and clinical research in childhood and adult TGCTs.

Terminal Deoxynucleotidyl Transferase Commonly Expresses in Germ Cell Tumors: Evaluation on a Large Series from Multiple Centers.

AimThe concrete features of expression of terminal deoxynucleotidyl transferase (TdT) are needed to be revealed in male and female germ cell tumors (GCTs).MethodsTdT immunostaining was performed in 195 GCTs, and the tumor and/or tumorous components included seminomas, germ cell neoplasias in situ (GCNISs), dysgerminomas, embryonal carcinomas (ECs), extragonadal germinomas, yolk sac tumors (YSTs), teratomas, and spermatocytic tumors. Twenty-one sex cord-stromal tumors were also added. Expression of the classical germ cell tumor markers (PLAP, OCT4, SALL4, CD117, and D2-40) was compared to that of TDT.ResultsNearly all (tumors or tumorous components) seminomas (99%, 107/108), GCNISs (98%, 51/52), dysgerminomas (94%, 17/18), ECs (100%, 15/15), and extragonadal germinomas (100%, 11/11) were positive for TdT. None of the cells in YSTs (0/38), teratomas (0/19), spermatocytic tumors (0/1), or sex cord-stromal tumors (0/21) were immunoreactive for TdT staining. The normal testicular and ovarian gonadal tissues were also negative for TdT. However, TdT presented with significant loss of antigen immunoreactivity in the paraffin-embedded tissues older than 3 years, giving rise to weak or moderate staining in a subset of cases. The expressions of TdT showed no significances with PLAP, OCT4, SALL4, CD117, and D2-40 during the diagnosis of the most GCTs (P>0.05), except for with PLAP, SALL4, or CD117 in YST (P=0.000 each), and D117 (P=0.000) or D2-40 (P=0.006) in ECs.ConclusionOur findings further verify that TdT can serve as a new GCT marker for seminomas, GCNISs, dysgerminomas, ECs, and extragonadal germinomas, with a highly positive rate. Awareness of TdT positivity in GCTs contributes to the prevention of erroneous diagnoses, particularly in the setting of core needle biopsies. To determine the properties where TdT staining may not be apparent in some old archived paraffin-embedded tissues, one could circumvent the potential misinterpretations of false-negative immunohistochemistry results.

Functional analysis of CG8005 gene in Drosophila testis

The processes of self-renewal and differentiation of germ cells are crucial to the development of male infertility and germ cell tumors. CG8005 gene is one of the regulatory factors of the testicular germ stem cells in Drosophila melanogaster, and its functional mechanism is still unknown. To explore the biological function(s) of CG8005 gene in the germ cell niche of Drosophila testis, first, the UAS-gal4 system was used to drive the expression of UAS-CG8005 RNAi in Drosophila testicular germ cells and cyst cells. Fertility tests were then performed to determine the fertility rate of male flies. Second, the expression patterns of Vasa, IBI, Zn finger homeodomain 1 (Zfh1), eyes absent (Eya), DE-cad, FasIII and Phospho-Histone H3(PH3), and TUNEL were analyzed by immunofluorescence staining in both control and CG8005 RNAi testes. Lastly, small interfering RNA (siRNA) was used to silence the CG8005 gene expression in Drosophila S2 cells; and PH3 was used to detect the proliferation ability of Drosophila S2 cells in the control group and CG8005 siRNA group. Apoptosis of Drosophila S2 cells was analyzed with TUNEL and flow cytometry. To observe the relative expression of the spliceosome, the mRNA levels of the spliceosome subunits were detected by fluorescence quantitative RT-PCR. As compared with the control group, the results showed that deletion of the CG8005 gene in the germ cells and cyst cells of the testis reduced or even completely abolished the fertility of male fruit flies. In addition, nos-gal4 driven UAS-CG8005 RNAi led to loss of fusomes and reduce the proliferative ability of germ cells. Noticeably, tj-gal4-directed UAS-CG8005 RNAi knockdown of CG8005 gene in the testis led to germ cell tumor development. Knockdown of CG8005 gene in Drosophila S2 cells resulted in increase in apoptosis and inhibition of proliferation. Further, the silencing of the CG8005 gene in Drosophila S2 cells caused increases in the mRNA levels of the spliceosome subunits. Hence, CG8005 gene is essential for the self-renewal and differentiation of germ cells in Drosophila testis. Its deletion may lead to restricted germ cell survival and the formation of germ cell-like tumors. CG8005 gene can participate in the regulation of proliferation and apoptosis of Drosophila S2 cells, which is essential for the maintenance of cell life, and might competitively regulate the mRNA levels of spliceosome subunits.

Incidence patterns of germ cell tumors in males and females from the surveillance, epidemiology, and end result nine registries (SEER9) from 1975-2016

Incidence patterns of germ cell tumors in males and females from the surveillance, epidemiology, and end result nine registries (SEER9) from 1975-2016