Overexpression of SerpinB9 in non-seminomatous germ cell tumors.

Serpinb9 is an inhibitor of granzyme B and is potentially involved in the immune escape of tumor cells. In the present study, bioinformatics analysis using open databases suggested that SerpinB9 is overexpressed in testicular embryonal carcinoma. Immunohistological analysis was performed on 28 cases of testicular germ cell tumors to investigate the relationship between SerpinB9 expression in testicular germ cell tumors and the tumor immune environment. SerpinB9 was significantly upregulated in the non-seminoma group and inversely correlated with the number of tumor-infiltrating CD8-positive cells. In addition, yolk sac tumors were characterized by the loss of human leukocyte antigen-class I expression. These findings suggest that SerpinB9 contributes to the immune escape of testicular germ cell tumors. Targeting therapy for SerpinB9 might therefore be useful in immunotherapy for testicular germ cell tumors resistant to immune checkpoint inhibitors.

Clinical Features and Survival Outcomes in Children and Adolescents With Malignant Mediastinal Germ Cell Tumors Based on Surveillance, Epidemiology, and End Results Database Analysis.

INTRODUCTION: The purpose of this study was to perform a population-based investigation to assess the disease characteristics and prognosis of children and adolescents with malignant mediastinal germ cell tumors (MMGCT). METHODS: Data on the demographics, treatment, and survival outcomes of children and adolescents with MMGCT from January 1, 2000 to December 31, 2018 were obtained. To compare survival curves, the log-rank test was employed. The generation of survival curves based on different parameters was done using Kaplan-Meier estimations. Cox proportional hazards regression was performed to determine the variables linked to disease-specific survival. RESULTS: The selection criteria were met by 152 MMGCT patients, 130 of whom were male. Fifty three cases of mixed germ cell tumors (GCTs), 41 cases of malignant teratomas, 26 cases of yolk sac tumors, 14 cases of seminoma, 13 cases of choriocarcinomas, and five cases of embryonal carcinoma were reported. Overall survival at 3 and 5 y for all patients was 63.1% and 61.2%, respectively. Malignant teratoma, yolk sac tumors, and mixed GCTs in children and adolescents had comparable survival rates, while those with choriocarcinoma and embryonal carcinoma showed the worst prognosis. Embryonal carcinoma, malignant teratoma, mixed GCTs, and choriocarcinoma were found as risk factors by multivariate Cox proportional hazards analysis. In contrast, surgery and younger age were protective factors. However, chemotherapy alone showed no survival benefits. CONCLUSIONS: Our population-based evidence showed that MMGCT had worse prognosis in older children and adolescents. Choriocarcinomas and embryonal carcinomas had the worst prognosis. Surgery can prolong survival time. Chemotherapy and radiotherapy were not associated with improved prognosis.

Survival of Testicular Pure Embryonal Carcinoma vs. Mixed Germ Cell Tumor Patients across All Stages.

Background and Objectives: The impact of pure histological subtypes in testicular non-seminoma germ cell tumors on survival, specifically regarding pure embryonal carcinoma, is not well established. Therefore, this study aimed to test for differences between pure embryonal carcinoma and mixed germ cell tumor patients within stages I, II and III in a large population-based database. Materials and Methods: We relied on the Surveillance, Epidemiology and End Results (SEER) database (2004-2019) to identify testicular pure embryonal carcinoma vs. mixed germ cell tumor patients. Cumulative incidence plots depicted cancer-specific mortality that represented the main endpoint of interest. Multivariable competing risks regression models tested for differences between pure embryonal carcinoma and mixed germ cell tumor patients in analyses addressing cancer-specific mortality and adjusted for other-cause mortality. Results: Of 11,223 patients, 2473 (22%) had pure embryonal carcinoma. Pure embryonal carcinoma patients exhibited lower cancer-specific mortality relative to their mixed germ cell tumor counterparts for both stage III (13.9 vs. 19.4%; p < 0.01) and stage II (0.5 vs. 3.4%, p < 0.01), but not in stage I (0.9 vs. 1.6%, p = 0.1). In multivariable competing risks regression models, pure embryonal carcinoma exhibited more favorable cancer-specific mortality than mixed germ cell tumor in stage III (hazard ratio 0.71, p = 0.01) and stage II (hazard ratio 0.11, p < 0.01). Conclusions: Pure embryonal carcinoma exhibits a more favorable cancer-specific mortality profile relative to mixed germ cell tumor in stage II and III testicular cancers. Consequently, the presence of mixed germ cell tumor elements may be interpreted as a risk factor for cancer-specific survival.

Germ cell neoplasms of the testis: Update for 2022.

Germ cell neoplasia in situ (GCNIS) is the precursor of both seminomatous and non-seminomatous germ cell tumors. It consists of distended tubules that may have either intratubular seminoma or intratubular embryonal carcinoma cells. Many invasive non-seminomatous tumors contain a mixture of tumor types, which are reviewed here. Morphology, aided by a panel of immunostains, can determine the presence and percent of embryonal carcinoma, yolk sac tumor, choriocarcinoma, or teratoma in such tumors. Use of immunostains, required for diagnosis in perhaps 25% of testicular neoplasms, is reviewed. Changes of classification in the AJCC (8th edition) in 2016 are discussed, including the partitioning of two tumor types: the central role of chromosome 12p amplification allows both teratoma and yolk sac tumor to be divided into prepubertal types (lacking amplification) and post-pubertal types. Occasionally, sex cord-stromal tumors, hematolymphoid tumors, or epididymal adenomatoid tumors enter the differential diagnosis of germ cell neoplasms.

Synchronous bilateral testicular cancer with discordant histopathology occurring in a 20-year-old patient: A case report and review of the literature.

INTRODUCTION: Bilateral testicular tumors are very rare, accounting for 1%-5% of all testicular germ-cell tumors (TGCTs). The vast majority of primary bilateral TGCTs are metachronous, with synchronous tumors comprising approximately 0.5%-1% of all cases. Those occurring synchronously share mostly the same histological pattern, predominantly seminoma, with synchronous bilateral TGCTs (SBTGCTs) with discordant subtypes being extremely rare. CASE PRESENTATION: We present the case of a 20-year-old male complaining of a palpable painless right testicular mass incidentally noticed during sexual intercourse. Ultrasonography (US) and magnetic resonance imaging (MRI) of the scrotum demonstrated bilateral testicular lesions, while staging with contrast-enhanced computed tomography (CT) exhibited normal findings. Right radical orchiectomy and left testis-sparing surgery (TSS) with concomitant onco-testicular sperm extraction (onco-TESE) were initially performed. Histology of the right testis revealed a mixed germ-cell tumor, consisting of seminoma and embryonal carcinoma, while that from the left testis disclosed embryonal carcinoma and intratubular germ-cell neoplasia unclassified (IGCNU) infiltrating the surgical margins. Hence, left orchiectomy was subsequently scheduled with histology unveiling IGCNU in the greatest part of the remaining testicular parenchyma. Following adjuvant chemotherapy, with bleomycin, etoposide, and cisplatin (BEP), the patient received testosterone replacement therapy and remained free of recurrence at an 18-month follow-up. CONCLUSION: This case highlights both the rarity of a bilateral testicular tumor's synchronous appearance and its extremely infrequent discordant histopathology. A comprehensive review of the major series of SBTGCTs with discordant histology cited in the literature is additionally presented.

[Current view on testicular tumors from a developmental biological perspective : Important biomarkers and molecular pathological investigations]. / Aktuelle Betrachtung der Hodentumoren aus entwicklungsbiologischer Sicht : Wichtige Biomarker und molekularpathologische Untersuchungen.

BACKGROUND: Germ cell tumors (GCTs) are the most common type of cancer in Germany in young men between 15 and 44 years of age. The routinely performed diagnostic procedures are essential for the patient's treatment, but can be difficult due to heterogenous histologies. Additionally, the molecular mechanisms of the development of the special forms growing teratoma syndrome (GTS) and testicular tumors with malignant somatic transformation (MST) as well as of therapy resistance are not fully understood. OBJECTIVES: Updated understanding of the molecular processes underlying GCT development and their special forms as well as recommendations for new and useful biomarkers. RESULTS: The development of GCTs is a dynamic process largely influenced by the microenvironment. Seminomas (SEs) in particular seem to posses a higher cellular plasticity than previously assumed, allowing SEs to be reprogrammed into an embryonal carcinoma (EC) or differentiate into extra-embryonal tissues (yolk sac tumors [YSTs], trophoblastic differentiation). Novel serological (mi371a-3p) and pathological (FOXA2) biomarkers are well suited to early detect GCTs and YSTs, respectively. For more aggressive tumors and special cases (GTS, MST), there are still no reliable diagnostics or specific/tailored therapies available. CONCLUSION: The ability of SEs to transit into EC or YSTs should be considered during therapy. Future research should focus on deciphering the special forms GTS and MST as well as the early recognition of YSTs, since their development seems to be an escape mechanism to chemotherapy.

SOX2 and PRAME in the "reprogramming" of seminoma cells.

BACKGROUND: In recent years, several studies investigated the complex process called "reprogramming" of seminoma (S) cells. The accepted pathogenetic model is a complex network including SOX2, SOX17, OCT3/4 and PRAME, which modulates the epigenetic transcription of numerous downstream genes and drives a divergent gene expression profile resulting in the transition from pure S (P-S) to S component (S-C) of mixed germ cell tumors of the testis (M-GCTT), and finally to embryonal carcinoma (EC). Herein, we tested a large cohort of GCTT with SOX2 and PRAME to evaluate their expression in the evolutionary steps of GCTT and verify if the modulation in the expression of these two molecules could be relevant for the fate of GCTT. METHODS: We tested 43, 19 and 17 consecutive and retrospectively enrolled cases of GCTT, germ cell neoplasia in situ (GCNIS) and uninvolved background testes (UBT), respectively. SOX2 and PRAME expressions have been evaluated with H-score and compared by adopting the appropriate statistic tests (Student's t-test and Mann-Whitney U test). RESULTS: We found that SOX2 was more expressed by nonseminomatous-GCTT (NS-GCTT) (p < 0.001) and EC (p < 0.001) rather than S; by contrast, PRAME showed an opposite expression profile being expressed by S but not by NS-GCTT (p < 0.001) and EC (p < 0.001). S-C showed different expressions of SOX2 and PRAME compared to both P-S (p = 0.002 and <0.001, respectively) and EC (p < 0.001 and 0.042, respectively), with intermediate values between these latter two categories. GCNIS and UBT showed no expression of SOX2 (scattered positive Leydig cells) but high H-score levels of PRAME. CONCLUSIONS: SOX2 and PRAME are differentially expressed and specularly modulated during the "reprogramming" of S cells [P-S (high levels of PRAME, no expression/low levels of SOX2) → S-C (intermediate levels of PRAME, intermediate levels of SOX2) → EC (no expression/low levels of PRAME, high levels of SOX2)], therefore supporting a complex pathogenetic model where the interactions between these two molecules are crucial in determining the fate of GCTT.

Prognostic factors in patients with clinical stage I nonseminoma-beyond lymphovascular invasion: a systematic review.

OBJECTIVE: To systematically evaluate evidence on prognostic factors for tumor recurrence in clinical stage I nonseminoma patients other than lymphovascular invasion (LVI). METHODS: We performed a systematic literature search in the biomedical databases Medline (via Ovid) and Cochrane Central Register of Controlled Trials (search period January 2010 to February 2021) for full text publications in English and German language, reporting on retro- or prospectively assessed prognostic factors for tumor recurrence in patients with stage I nonseminomatous germ cell tumors. RESULTS: Our literature search yielded eleven studies reporting on 20 potential prognostic factors. Results are based on cohort studies of mostly moderate to low quality. Five out of eight studies found a significant association of embryonal carcinoma (EC) in the primary tumor with relapse. Among the different risk definitions of embryonal carcinoma (presence, predominance, pure), presence of EC alone seems to be sufficient for prognostification. Interesting results were found for rete testis invasion, predominant yolk sac tumor, T-stage and history of cryptorchidism, but the sparse data situation does not justify their clinical use. CONCLUSIONS: No additional factors that meet the prognostic value of LVI, especially when determined by immunohistochemistry, could be identified through our systematic search. The presence of EC might serve as a second, subordinate prognostic factor for clinical use as the data situation is less abundant than the one of LVI. Further efforts are necessary to optimize the use of these two prognostic factors and to evaluate and validate further potential factors with promising preliminary data.

The signal transducer CD24 suppresses the germ cell program and promotes an ectodermal rather than mesodermal cell fate in embryonal carcinomas.

Testicular germ cell tumors (GCTs) are stratified into seminomas and nonseminomas. Seminomas share many histological and molecular features with primordial germ cells, whereas the nonseminoma stem cell population-embryonal carcinoma (EC)-is pluripotent and thus able to differentiate into cells of all three germ layers (teratomas). Furthermore, ECs are capable of differentiating into extra-embryonic lineages (yolk sac tumors, choriocarcinomas). In this study, we deciphered the molecular and (epi)genetic mechanisms regulating expression of CD24, a highly glycosylated signaling molecule upregulated in many cancers. CD24 is overexpressed in ECs compared with other GCT entities and can be associated with an undifferentiated pluripotent cell fate. We demonstrate that CD24 can be transactivated by the pluripotency factor SOX2, which binds in proximity to the CD24 promoter. In GCTs, CD24 expression is controlled by epigenetic mechanisms, that is, histone acetylation, since CD24 can be induced by the application histone deacetylase inhibitors. Vice versa, CD24 expression is downregulated upon inhibition of histone methyltransferases, E3 ubiquitin ligases, or bromodomain (BRD) proteins. Additionally, three-dimensional (3D) co-cultivation of EC cells with microenvironmental cells, such as fibroblasts, and endothelial or immune cells, reduced CD24 expression, suggesting that crosstalk with the somatic microenvironment influences CD24 expression. In a CRISPR/Cas9 deficiency model, we demonstrate that CD24 fulfills a bivalent role in differentiation via regulation of homeobox, and phospho- and glycoproteins; that is, it is involved in suppressing the germ cell/spermatogenesis program and mesodermal/endodermal differentiation, while poising the cells for ectodermal differentiation. Finally, blocking CD24 by a monoclonal antibody enhanced sensitivity toward cisplatin in EC cells, including cisplatin-resistant subclones, highlighting CD24 as a putative target in combination with cisplatin.

Overexpression of melanoma-associated antigen A2 has a clinical significance in embryonal carcinoma and is associated with tumor progression.

INTRODUCTION: Melanoma-associated antigen A2 (MAGE-A2) is a member of the cancer-testis antigen family differentially overexpressed in a variety of malignancies and is associated with tumor development. However, clinical significance and prognostic value of MAGE-A2 in different histological subtypes of testicular germ cell tumors (TGCTs) have not been explored. MATERIALS AND METHODS: Here, we aimed to investigate the clinical significance and prognostic impact of MAGE-A2 expression in TGCTs compared to benign tumors as well as adjacent normal tissues and then between seminomas and non-seminomas groups using immunohistochemistry on tissue microarrays. RESULTS: The results indicated a statistically significant difference between overexpression of MAGE-A2 and histological subtypes of TGCTs. A statistically significant association was found between a high level of nuclear expression of MAGE-A2 protein and advanced pT stage (P = 0.022), vascular invasion (P = 0.037), as well as involvement of rete testis (P = 0.022) in embryonal carcinomas. Increased nuclear expression of MAGE-A2 was observed to be associated with more aggressive behaviors and tumor progression rather than cytoplasmic expression in these cases. Further, high level nuclear expression of MAGE-A2 had shorter disease-specific survival (DSS) or progression-free survival (PFS) compared to patients with moderate and low expression of MAGE-A2, however, without a statistically significant association. CONCLUSION: Our results confirm that increased nuclear expression of MAGE-A2 has a clinical significance in embryonal carcinomas and is associated with progression of disease. Moreover, MAGE-A2 may act as a potential predictive biomarker for the prognosis in embryonal carcinomas if follow-up period becomes longer. Further investigations for the biological function of MAGE-A2 are required in future studies.

Comprehensive characteristics of pathological subtypes in testicular germ cell tumor: Gene expression, mutation and alternative splicing.

Background: Testicular germ cell tumor (TGCT) is the most common tumor in young men, but molecular signatures, especially the alternative splicing (AS) between its subtypes have not yet been explored. Methods: To investigate the differences between TGCT subtypes, we comprehensively analyzed the data of gene expression, alternative splicing (AS), and somatic mutation in TGCT patients from the TCGA database. The gene ontology (GO) enrichment analyses were used to explore the function of differentially expressed genes and spliced genes respectively, and Spearman correlation analysis was performed to explore the correlation between differential genes and AS events. In addition, the possible patterns in which AS regulates gene expression were elaborated by the ensemble database transcript atlas. And, we identified important transcription factors that regulate gene expression and AS and functionally validated them in TGCT cell lines. Results: We found significant differences between expression and AS in embryonal carcinoma and seminoma, while mixed cell tumors were in between. GO enrichment analyses revealed that both differentially expressed and spliced genes were enriched in transcriptional regulatory pathways, and obvious correlation between expression and AS events was determined. By analyzing the transcript map and the sites where splicing occurs, we have demonstrated that AS regulates gene expression in a variety of ways. We further identified two pivot AS-related molecules (SOX2 and HDAC9) involved in AS regulation, which were validated in embryonal carcinoma and seminoma cell lines. Differences in somatic mutations between subtypes are also of concern, with our results suggesting that mutations in some genes (B3GNT8, CAPN7, FAT4, GRK1, TACC2, and TRAM1L1) occur only in embryonal carcinoma, while mutations in KIT, KARS, and NRAS are observed only in seminoma. Conclusions: In conclusion, our analysis revealed the differences in gene expression, AS and somatic mutation among TGCT subtypes, providing a molecular basis for clinical diagnosis and precise therapy of TGCT patients.

A preliminary study investigating the detection of lymphovascular invasion in germ cell tumors of the testis with double staining for OCT4/CD34.

Lymphovascular invasion (LVI) is a relevant prognostic factor in germ cell tumors of the testis (GCTT) and it has been included in the AJCC staging system. Nevertheless, its histological assessment is challenging, with low/moderate interobserver agreement also among expert uropathologists. Few studies focused on the potential role of immunohistochemistry to solve this critical issue; as result, in current guidelines there is no indication for additional staining to detect this histological feature. In the present study, we investigated the detection of LVI invasion in a small cohort of GCTT with double staining for OCT4/CD34. Although our results need to be validated in larger case series with follow-up data, they suggest as OCT4/CD34 could be a useful tool for the histological assessment of these tumors, helping to identify some histological mimickers of LVI and modifying the pT/stage in a significant percentage of patients.

Outcomes of post-chemotherapy robot-assisted retroperitoneal lymph node dissection in testicular cancer: multi-institutional study.

OBJECTIVE: To evaluate the perioperative and oncological outcomes after post-chemotherapy robot-assisted retroperitoneal lymph node dissection (PC-RARPLND). MATERIALS AND METHODS: We retrospectively reported the perioperative and oncological outcomes of all the patients with testicular cancer who underwent PC-RARPLND at three tertiary teaching centers. Descriptive statistical measures were used to report demographic, clinical, intraoperative, postoperative and oncological outcomes. RESULTS: There were 43 consecutive patients who underwent PC-RARPLND at the participating institutions. Mean patient age was 29.2 years (± 8.2), BMI was 26.6 kg/m2 (± 6.2). The mean size of retroperitoneal mass was 4.1 cm (± 3.5). Full bilateral template dissection was performed in 38 (88.3%) patients. Nerve sparing was attempted in 19 (44.1%) patients. Mean operative time was 374 min (± 132) and estimated blood loss was 292 ml (± 445.6). The mean postoperative LOS was 2.8 days (± 5.9). There was a total of 12 complications in 10 patients (Clavien grade I = 5, II = 3, III = 3 and IV = 1). Postoperative pathology demonstrated 24 patients (55%) with necrosis/fibrosis, 16 (37%) with teratoma and 3 (7%) with viable tumor. Mean lymph node (LN) yield was 26.5 LNs (SD ± 16.1). Patients were followed for a mean of 30.7 months (± 24.7). No deaths were documented during follow-up and 2 pulmonary recurrences were identified. Antegrade ejaculation was preserved in 70.6% of patient who underwent nerve sparing. Limitations included retrospective nature and limited follow up. CONCLUSION: PC-RAPLND is safe and technically reproducible. It provides improved morbidity and less convalescence.

Malignant Mixed Germ Cell Tumors of the Ovary: An Analysis of 100 Cases Emphasizing the Frequency and Interrelationships of Their Tumor Types.

One hundred malignant mixed germ cell tumors of the ovary that occurred in patients 3 to 55 years (mean: 20 y) of age are described. The clinical presentation was usually that of any highly malignant tumor of the ovary (abdominal pain and distension), but rarely (3 cases) endocrine manifestations were present. The tumors were usually unilateral (96%), ranged from 4 to 38 cm (mean: 16 cm), and were uniformly solid or, more often, solid and cystic; occasionally the typical appearance of dysgerminoma could be appreciated. The most common tumor type was yolk sac tumor (91%), followed by dysgerminoma (61%), immature teratoma (58%), embryonal carcinoma (38%), and choriocarcinoma (11%). A variety of admixtures were encountered; dysgerminoma and yolk sac tumor was the most common combination (25% of the tumors) with the 2 components often being sharply demarcated. Immature teratoma and yolk sac tumor was the next most common pairing (20%) followed by yolk sac tumor and embryonal carcinoma, with or without immature teratoma (16%). Tumors with a choriocarcinoma component had the most varied combinations of tumor types. Embryoid bodies were seen in 21% of the tumors, most often as fragmented forms arranged in a nodular manner with yolk sac tumor and/or embryonal carcinoma; uncommonly they occurred singly or in clusters. Numerous confluent well-formed embryoid bodies (polyembryoma) were prominent in 2 tumors. Three tumors had a focal diffuse embryoma pattern. The specific tumor types showed the known diverse spectrum of microscopic appearances, but the frequent haphazard arrangement of 2 or more subtypes often resulted in complex morphology. Overgrowth of another neoplastic component, most often primitive neuroectodermal tumor, occurred in 10% of the tumors further complicating the histologic picture. This is the largest series of ovarian malignant mixed germ cell tumors reported and details their characteristics including associations of their subtypes and the frequent apparent role of embryoid bodies in giving rise to yolk sac tumor and embryonal carcinoma components.

The PI3K/AKT Pathway Is Activated by HGF in NT2D1 Non-Seminoma Cells and Has a Role in the Modulation of Their Malignant Behavior.

Overactivation of the c-MET/HGF system is a feature of many cancers. We previously reported that type II testicular germ cell tumor (TGCT) cells express the c-MET receptor, forming non-seminomatous lesions that are more positive compared with seminomatous ones. Notably, we also demonstrated that NT2D1 non-seminomatous cells (derived from an embryonal carcinoma lesion) increase their proliferation, migration, and invasion in response to HGF. Herein, we report that HGF immunoreactivity is more evident in the microenvironment of embryonal carcinoma biopsies with respect to seminomatous ones, indicating a tumor-dependent modulation of the testicular niche. PI3K/AKT is one of the signaling pathways triggered by HGF through the c-MET activation cascade. Herein, we demonstrated that phospho-AKT increases in NT2D1 cells after HGF stimulation. Moreover, we found that this pathway is involved in HGF-dependent NT2D1 cell proliferation, migration, and invasion, since the co-administration of the PI3K inhibitor LY294002 together with HGF abrogates these responses. Notably, the inhibition of endogenous PI3K affects collective cell migration but does not influence proliferation or chemotactic activity. Surprisingly, LY294002 administered without the co-administration of HGF increases cell invasion at levels comparable to the HGF-administered samples. This paradoxical result highlights the role of the testicular microenvironment in the modulation of cellular responses and stimulates the study of the testicular secretome in cancer lesions.

Expression and roles of system L amino acid transporters in human embryonal carcinoma cells.

BACKGROUND: Testicular germ cell tumors (TGCTs) are the most common malignant cancer in young men. Although TGCTs are generally responsive to platinum-based chemotherapy particularly cisplatin, acquired resistance in patients with metastasis still occurs resulting in poor prognosis. Specifically, differentiation of embryonal carcinoma (EC) cells, the stem cells of TGCTs, can lead to the reduction of cisplatin responsiveness. Therefore, novel therapeutic strategies for TGCTs are needed. System L amino acid transporters have been reported to be up-regulated and to play an important role in tumorigenesis. However, expression and role of system L amino acid transporters in TGCTs remain elusive. MATERIALS AND METHODS: Expression of system L amino acid transporters was analyzed in TGCT samples from The Cancer Genome Atlas (TCGA). Expression of LAT1, LAT2, and 4F2hc was examined in human embryonal carcinoma cell line NTERA2. Roles of system L amino acid transporters on NTERA2 cell survival, cell proliferation, pluripotency, and cisplatin sensitivity were evaluated. RESULTS: Based upon TCGA datasets, we found that two isoforms of system L (LAT1 and LAT2) and their chaperone protein 4F2hc are highly expressed in EC samples compared with other groups. Treatment with the system L inhibitor BCH significantly suppressed leucine uptake into the pluripotent EC cell line NTERA2. The malignant phenotypes including cell viability, cell proliferation, and clonal ability were decreased following BCH treatment. Nonetheless, system L inhibition did not alter expression of stemness genes in NTERA2 cells. After NTERA2 differentiation, expressions of LAT1 and LAT2 were decreased. Finally, co-administration of BCH enhanced cisplatin sensitivity in both undifferentiated and differentiated cells. These effects were associated with the reduction in p70S6K phosphorylation. CONCLUSION: Taken together, these results shed light on the roles of system L amino acid transporters in TGCTs. Therefore, system L amino acid transporters could provide novel therapeutic targets for treatment against TGCTs.

Low level expression of human telomerase reverse transcriptase predicts cancer-related death and progression in embryonal carcinoma.

INTRODUCTION: hTERT (human telomerase reverse transcriptase) is a catalytic subunit of the enzyme telomerase and has a role in cell proliferation, cellular senescence, and human aging. MATERIALS AND METHODS: The purpose of this study was to evaluate the expression and significance of hTERT protein expression as a prognostic marker in different histological subtypes of testicular germ cell tumors (TGCTs), including 46 embryonal carcinomas, 46 yolk sac tumors, 38 teratomas, 84 seminomas as well as two main subtypes of seminomas and non-seminomas using tissue microarray (TMA) technique. RESULTS: The results showed that there is a statistically significance difference between the expression of hTERT and various histological subtypes of TGCTs (P < 0.001). In embryonal carcinoma, low level expression of hTERT protein was significantly associated with advanced pT stage (P = 0.023) as well as tunica vaginalis invasion (P = 0.043). Moreover, low level expression of hTERT protein was found to be a significant predictor of worse DSS (log rank: P = 0.011) and PFS (log rank: P = 0.011) in the univariate analysis. Additionally, significant differences were observed (P =0.021, P =0.018) with 5-year survival rates for DSS and PFS of 66% and 70% for moderate as compared to 97% and 97% for high hTERT protein expression, respectively. CONCLUSION: We showed that hTERT protein expression was associated with more aggressive tumor behavior in embryonal carcinoma patients. Also, hTERT may be a novel worse prognostic indicator of DSS or PFS, if the patients are followed up for more time periods.

Fermented Ginseng Extract, BST204, Suppresses Tumorigenesis and Migration of Embryonic Carcinoma through Inhibition of Cancer Stem Cell Properties.

The pharmacological effects of BST204-a fermented ginseng extract-on several types of cancers have been reported. However, the effects of ginseng products or single ginsenosides against cancer stem cells are still poorly understood. In this study, we identified the anti-tumorigenic and anti-invasive activities of BST204 through the suppression of the cancer stem cell marker, CD133. The treatment of embryonic carcinoma cells with BST204 induced the expression of the tumor suppressor protein, p53, which decreased the expression of cell cycle regulatory proteins and downregulated the expression of CD133 and several stemness transcription factors. These changes resulted in both the inhibition of tumor cell proliferation and tumorigenesis. The knockdown of CD133 suggests that it has a role in tumorigenesis, but not in cancer cell proliferation or cell cycle arrest. Treatment with BST204 resulted in the reduced expression of the mesenchymal marker, N-cadherin, and the increased expression of the epithelial marker, E-cadherin, leading to the suppression of tumor cell migration and invasion. The knockdown of CD133 also exhibited an anti-invasive effect, indicating the role of CD133 in tumor invasion. The single ginsenosides Rg3 and Rh2-major components of BST204-exhibited limited effects against cancer stem cells compared to BST204, suggesting possible synergism among several ginsenoside compounds.

HNF1ß is a sensitive and specific novel marker for yolk sac tumor: a tissue microarray analysis of 601 testicular germ cell tumors.

Hepatocyte Nuclear Factor 1 beta (HNF1ß) is a transcription factor which plays an important role during early organogenesis, especially of the pancreato-biliary and urogenital tract. Furthermore, HNF1ß is an established marker in the differential diagnosis of ovarian cancer and shows a distinct nuclear expression in the clear cell carcinoma subtype. Recently, it has been described in yolk sac tumor, which represents a common component in many non-seminomatous germ cell tumors. Due to its broad histologic diversity, the diagnosis may be challenging and additional tools are very helpful in the workup of germ cell tumors. Immunohistochemistry was used to study HNF1ß expression in a tissue microarray (TMA) of 601 testicular germ cell tumors including seminoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, teratoma, germ cell neoplasia in situ (GCNIS), and normal tissue. The expression pattern was compared to glypican 3 (GPC3) and α-fetoprotein (AFP), two markers currently in use for the detection of yolk sac tumor. HNF1ß showed a distinct nuclear staining in comparison to the cytoplasmic pattern of GPC3 and AFP. The sensitivity and specificity of HNF1ß were 85.4% and 96.5%, of GPC3 83.3% and 90.7%, of AFP 62.5% and 97.7%. We conclude that HNF1ß allows a reliable distinction of yolk sac tumor from other germ cell tumor components. Therefore, we propose HNF1ß as a novel and robust marker in the immunohistochemical workup of testicular germ cell tumors.