Origin Of Germ Cell Tumors Research Articles

P53 Overexpression May Represent an Early Marker of Clinicopathologic Progression in Vasculogenic Mesenchymal Lesions of Germ Cell Tumor Origin.

Vasculogenic mesenchymal lesions (VMLs) of germ cell tumor origin are thought to originate in postpubertal-type yolk sac tumor componentsand include a spectrum of lesions from teratoma with vasculogenic stroma (TVS), to low and high-grade vasculogenic mesenchymal tumors (VMTs). VMLs exhibit rudimentary to well-developed neoplastic vessels within primitive mesenchyme, being considered a neoplastic reiteration of embryonic vasculogenesis in the splanchnic mesoderm of the yolk sac. They occur in patients with primary mediastinal germ cell tumors after chemotherapy, and a subset progresses to "somatic-type" sarcomas [including angiosarcoma (AS)], with high-grade VMTs likely portending a higher risk. Recently, we encountered a low-grade VMT that progressed to metastatic AS during follow-up. In this case, both the low-grade VMT and the subsequent AS demonstrated p53 overexpression, suggesting that p53 alterations may precede histopathologic transformation. To test this hypothesis, we evaluated neoplasms representing the entire spectrum of VMLs using p53 immunohistochemistry (IHC; clone DO-7, Dako). Overexpression was defined as nuclear positivity in > 80% of neoplastic cells. Because the distinction between high-grade VMT and AS can be subjective in some cases, they were grouped together in a single category. Thirty-nine VMLs were assessed: 16 high-grade VMT/AS, 19 low-grade VMT, and 4 TVS. Patient age ranged from 19 to 46 years (mean, 30 years; male = 97%). Four high-grade VMT/AS and one low-grade VMT showed p53 overexpression (5/39 VMLs, 13%; 4/16 high-grade VMT/AS, 25%). These tumors included 1 unequivocal AS and 1 high-grade VMT/AS with progression to rhabdomyosarcoma. The only low-grade VMT with p53 overexpression demonstrated progression to AS. Another high-grade VMT that progressed to sarcoma demonstrated p53 overexpression in the sarcoma component, but it was excluded because the VMT was not represented in the material availableat the time of the study. Lesions with intratumoral grade heterogeneity (classified based the highest grade), demonstrated more pronounced p53 overexpression in the high-grade components. P53 overexpression is associated with disease progression in a subset of VMTs and may precede morphologic transformation to sarcoma. Routine evaluation of VMTs with p53 IHC seems justified, with overexpressors likely requiring an close clinical surveillance.

An in vitro three-dimensional (3D) testicular organoid culture system for efficient gonocyte maintenance and propagation using frozen/thawed neonatal bovine testicular tissues

Fertility preservation in prepubertal boys with cancer requires the cryopreservation of immature testicular tissues (ITTs) prior to gonadotoxic treatment. However, the limited number of germ cells in small human ITT biopsies necessitates the development of an in vitro culture system for germ cell expansion using frozen-thawed ITTs. Here, we generated testicular organoids for the in vitro maintenance and expansion of gonocytes from frozen-thawed two-week-old neonatal bovine ITTs. We investigated the effects of different cell-seeding densities, culture serums, seeding methods, and gonadotropin supplementations, on the maintenance and proliferation of enriched gonocytes. Our results demonstrated that enriched gonocytes and testicular cells from frozen-thawed neonatal ITTs could self-assemble into spheroid organoids in three days in an appropriate Matrigel-based culture environment. For the optimal formation of prepubertal testicular organoids, a seeding density of 1 × 106 cells/well is recommended over other densities. This strategy results in organoids with a mean diameter of 60.53 ± 12.12 μm; the mean number of organoids was 5.57 ± 1.60/105 μm2 on day 11. The viability of organoids was maintained at 79.75 ± 2.99% after being frozen and thawed. Supplementing the culture medium with glial cell-derived neurotrophic factor, fibroblast growth factor 2, and leukemia inhibitory factor, increased the proportion of KI67-positive proliferating cells in organoids, elevated the expression of C-KIT but reduced the expression of GFRα1 at day 28 when compared to those without hormone supplements (p< 0.05). In addition, supplementing the culture medium with follicle-stimulating hormone and testosterone helped to maintain a significantly higher viability (p< 0.05) in ITT organoids at day 28. These organoids could be cryopreserved for storage and thawed as needed. The successful generation of ITT organoids provides a valuable tool for establishing in vitro spermatogenesis, propagating human germ cells, investigating testicular physiology and the origin of germ cell tumors, and testing the toxicity of new drugs in future clinical applications.

Stay on the road: from germ cell specification to gonadal colonization in mammals.

The founder cells of the gametes are primordial germ cells (PGCs). In mammals, PGCs are specified early during embryonic development, at the boundary between embryonic and extraembryonic tissue, long before their later residences, the gonads, have developed. Despite the differences in form and behaviour when differentiated into oocytes or sperm cells, in the period between specification and gonadal colonization, male and female PGCs are morphologically indistinct and largely regulated by similar mechanisms. Here, we compare different modes and mechanisms that lead to the formation of PGCs, putting in context protocols that are in place to differentiate both human and mouse pluripotent stem cells into PGC-like cells. In addition, we review important aspects of the migration of PGCs to the gonadal ridges, where they undergo further sex-specific differentiation. Defects in migration need to be effectively corrected, as misplaced PGCs can become tumorigenic. Concluding, a combination of in vivo studies and the development of adequate innovative in vitro models, ensuring both robustness and standardization, are providing us with the tools for a greater understanding of the first steps of gametogenesis and to develop disease models to study the origin of germ cell tumours.This article is part of the theme issue ‘Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom’.

Germ cell determination and the developmental origin of germ cell tumors.

In each generation, the germline is tasked with producing somatic lineages that form the body, and segregating a population of cells for gametogenesis. During animal development, when do cells of the germline irreversibly commit to producing gametes? Integrating findings from diverse species, we conclude that the final commitment of the germline to gametogenesis - the process of germ cell determination - occurs after primordial germ cells (PGCs) colonize the gonads. Combining this understanding with medical findings, we present a model whereby germ cell tumors arise from cells that failed to undertake germ cell determination, regardless of their having colonized the gonads. We propose that the diversity of cell types present in these tumors reflects the broad developmental potential of migratory PGCs.

Signet Ring Cell Carcinoma of the Testis

Development of a somatic-type malignancy from a mixed germ cell tumor is a rare but recognized event and typically represented by sarcoma or, less commonly, by carcinoma. This phenomenon is generally believed to result from progression of a teratomatous component. In many cases, because of intermingling of other germ cell tumor components, the diagnosis is apparent; however, in rare cases, metastatic carcinoma to the testis or a novel primary tumor may be a diagnostic consideration. In this study, we report the clinicopathologic, immunohistochemical, and molecular features of a 53-year-old man, whose testicular tumor was composed entirely of signet ring cells, mimicking metastatic carcinoma. Subsequent retroperitoneal lymph node dissection revealed metastatic deposits composed of teratoma and yolk sac tumor, in addition to signet ring cell carcinoma. Fluorescence in situ hybridization for abnormalities of chromosome 12p revealed the presence of i(12p) in both the teratoma and signet ring cell carcinoma in the metastasis and in signet ring cells in the testis, supporting a common germ cell origin. Our report indicates that signet ring carcinoma cells in an orchiectomy specimen, although usually strongly suggestive of metastatic adenocarcinoma from a primary tumor in another organ, may be a primary testicular neoplasm of germ cell tumor origin. This is the first report of testicular signet ring cell carcinoma of germ cell tumor derivation.

The Control of Cell Cycle in Mouse Primordial Germ Cells: Old and New Players

The cell cycle of primordial germ cells (PGCs), the embryonic precursors of gametes, is characterized by a mitotic phase common to both sexes and a mitotic-meiotic switch in the female. In the present work, we will review the results obtained in the last decade by studies aimed to clarify intrinsic and extrinsic regulatory signals of such processes, with particular reference to mouse PGCs. Besides providing a better understanding of how the gamete population is established in mammals, information about the players controlling the PGC cycle will be useful to clarify other intriguing aspects of germ cell biology such as the origin of germ cell tumours and the mechanisms allowing the maintenance of totipotency in the germ line.

Outcome analysis of patients with transformed teratoma to primitive neuroectodermal tumor

BackgroundThe emergence of a primitive neuroectodermal tumor (PNET) within a germ-cell tumor (GCT) is rare. We assess the prognosis and response to treatment. Patients and methodsEighty-one patients were identified. Selected patients were treated with cyclophosphamide 1200 mg/m2, doxorubicin 75 mg/m2, and vincristine 2 mg i.v. alternating with ifosfamide 1.8 g/m2 × 5 days plus etoposide 100 mg/m2 × 5 days (CAV/IE). Ewing's sarcoma (EWS) translocation was assessed using a FISH-based method. ResultsMedian follow-up was 41 months. Seventy-six patients had PNET in the primary tumor or in initial metastasis. Five harbored PNET only at relapse. Twenty-six of 76 underwent primary retroperitoneal lymph node dissection, 13 of whom had retroperitoneal PNET and four are dead of disease (DOD). Fifty of 76 were initially treated with GCT chemotherapy (n = 49) or CAV/IE (n = 1). Twenty-seven of these 50 underwent complete postchemotherapy resection of residual PNET and 17 are DOD. Ten patients received CAV/IE. Eight achieved an objective response, and five are currently alive. One of the 14 specimens examined carried the EWS translocation. ConclusionsPNET of GCT origin is associated with an adverse outcome. For low-volume disease, surgery is the optimal initial therapy. CAV/IE may have a role in patients with unresectable disease.

Technique of Mediastinal Germ Cell Tumor Resection

The anterior mediastinum represents the second most common site of germ cell tumor origin. Nonseminomatous germ cell cancers not only comprise the main category of the malignant germ cell tumors arising in the mediastinum (PMNSGCT) but also the most challenging from both oncologic and surgical standpoints. Although histologically similar to their more commonly occurring testicular counterparts, PMNSGCT have an overall worse prognosis and therefore have been categorized as “poor risk” along with other subsets of testicular nonseminomatous germ cell tumors. The majority of PMNSGCTs occur in males 20 to 40 years of age. Most patients present symptomatic secondary to a rapidly growing anterior mediastinal mass. Computed tomographic (CT) scans typically demonstrate a large heterogeneous mass. Local invasion into lung, great vein, and pericardium is common and even direct cardiac chamber/proximal great artery involvement can occasionally be present. Associated pericardial and pleural effusions are also common but typically not malignant in nature. For any young adult male presenting with a mass in the anterior mediastinal compartment, obtaining serum tumor markers (STMs), alpha-fetoprotein, and human chorionic gonadotropin is an essential component of clinical evaluation as significant elevation of either STM is diagnostic for PMNSGCT. Biopsy in these cases is not only unnecessary but can be misleading due to sampling error within these typically large and heterogeneous neoplasms. We believe biopsy confirmation is only necessary in rare PMNSGCT patients presenting with normal STMs or patients with minor elevations of human chorionic gonadotropin, which can be present in pure seminomatous germ cell cancer. Histologically, these neoplasms comprise at least one nonseminomatous germ cell cancer subtype (yolk sac cancer, embryonal carcinoma, or choriocarcinoma in order of frequency), and frequently are mixed with some form of pathologic teratoma ranging from mature teratoma to teratoma with immature elements (“stromal aytpia”), and finally, to frank malignant degeneration of teratoma into the so-called “nongerm cell” cancer (sarcomas and epithelial carcinomas). Chest and abdominal CT scans are standard imaging tests for staging with other radiologic studies including positron emission tomography scan and central nervous system magnetic resonance imaging obtained on an individual basis. Gated magnetic resonance imaging or echocardiogram can be helpful to determine the presence of great vessel or cardiac involvement; however, invasion may be subtle and only apparent at the time of postchemotherapy surgical resection. We therefore have cardiopulmonary bypass capabilities available for these cases. After diagnosis and staging, surgical resection for PMNSGCT as initial therapy will rarely achieve local control and does not treat metastatic disease, present in 20 to 25% of cases. Appropriate therapy typically begins with cisplatin-based chemotherapy. Over the past 3 years we have utilized etoposide,

New Insights into Germ Cell Tumor Formation

Recent years have witnessed a number of new findings with significant implications for our understanding of the development of germ cell tumors. This communication reviews some of these recent insights with an emphasis on mechanisms that may convert a germ cell into a tumor cell. Three aspects are discussed in this review: (1) the early origin of germ cell tumors from primordial germ cells through an aberrant mitosis-to-meiosis switch; (2) errors during meiosis, which promote tumorigenic transformation of germ cells; and (3) the role of small RNAs such as oncomirs (miRNAs) and oncopirs (piRNAs) in germ cell tumor formation. Since much has been learned using a variety of organismal models, data obtained in experiments with mice, nematodes, fruit flies, and human data will be considered. Only exemplary references are included.

Unusual scapular metastasis as initial manifestation of advanced nonseminomatous germ cell tumor of the mediastinum

Primary malignant germ cell tumors of the mediastinum are relatively rare, occurring predominantly in young male adults, and have a poor prognosis. We present a case of a 27-year-old man who initially experienced a persistent, intractable painful sensation over the right lower scapula despite taking an analgesic agent for 2 months. A scapular x-ray film and a whole-body bone scan showed an expansile osteolytic lesion. Excisional biopsy of the scapula revealed a metastatic carcinoma, suggestive of nonseminomatous germ cell tumor origin. Further examination of the whole abdomen and bilateral testes were negative. Chest computed tomography and magnetic resonance imaging showed a primary tumor mass in the anterior mediastinum. Chemotherapy with cisplatin, bleomycin, and etoposide was administered for six courses. The mediastinal tumor mass was markedly reduced in size and remission without evidence of tracer uptake by [(18)F]fluorodeoxyglucose positron emission tomography examination. Six months after chemotherapy, the patient received advanced surgical intervention to remove the mediastinal tumor, the pathologic features of which were similar to the previous scapular lesion. He was doing well at 1-year follow-up.

Intra‐abdominal desmoid tumor following retroperitoneal lymph node dissection for testicular germ cell tumor

In the testicular cancer post-treatment setting a rapidly growing retroperitoneal mass leads to a differential diagnosis including recurrent germ cell tumor, residual mature teratoma, or sarcomatoid degeneration. We report the case of a 27-year-old man with a large abdominal mass occurring in the setting of a mixed germ cell tumor after radical orchiectomy with primary chemotherapy followed by retroperitoneal lymph node dissection. Surgical excision of this mass followed by pathological review revealed an intra-abdominal desmoid tumor. Fluorescence in situ hybridization (FISH) for isochromosome 12p failed to demonstrate a germ cell tumor origin. This is the fourth such case of an intra-abdominal desmoid tumor after retroperitoneal lymph node dissection for testicular cancer in the urologic literature. This case highlights the need for careful consideration of a desmoid tumor when a rapidly growing spindle cell tumor is encountered in a post-treatment testis cancer patient.

IGF2/H19 imprinting analysis of human germ cell tumors (GCTs) using the methylation‐sensitive single‐nucleotide primer extension method reflects the origin of GCTs in different stages of primordial germ cell development

Previous studies have demonstrated biallelic expression of the imprinted genes H19 and IGF2 and loss of DNA methylation of the SNRPN gene, indicating a common precursor cell of human germ cell tumors (GCTs), namely, the primordial germ cell (PGC). In this study, we applied the methylation-sensitive single-nucleotide primer extension (MS-SNuPE) technique to the analysis of the IGF2/H19 imprinting control region (ICR) in 55 GCTs from representative clinical and histologic subgroups. Most GCTs showed low methylation at the IGF2/H19 ICR. All 8 ovarian GCTs, 9 of 10 testicular seminomas, 7 of 10 testicular nonseminomas (all in adolescents/adults), 6 of 9 testicular yolk sac tumors (YSTs), and 12 of 14 nongonadal GCTs (all in infants/children) were hypomethylated. The highest methylation was observed in three childhood YSTs (boys) and 2 of 4 spermatocytic seminomas. The latter are derived from more advanced stages of germ-cell development. The predominantly low methylation of most of the other GCTs correlates with studies that demonstrated erasure of the methylation imprint of the IGF2/H19 ICR during embryonal PGC migration and development. These findings suggest that the IGF2/H19 methylation status in GCTs might reflect preservation of the physiologic imprinting erasure in PGCs rather than a loss of imprinting in a sense that is accepted for somatic tumors. Furthermore, this study indicates that imprinting control mechanisms other than the proposed CTCF (CCCTC binding factor) boundary model regulate IGF2 expression during this stage of PGC development as well as in GCTs derived from PGC. (c) 2005 Wiley-Liss, Inc.

Chemotherapy for teratoma with malignant transformation.

Teratoma with malignant transformation (MT) is a well-described entity that refers to the MT of a somatic teratomatous component in a germ cell tumor (GCT) to a histology that is identical to a somatic malignancy (eg, rhabdomyosarcoma [RMS]). Surgical resection has been the mainstay of therapy for localized transformed disease because these tumors are thought to be resistant to standard treatment. We report that chemotherapy has a role in selected patients with MT, determined by cell type. Chemotherapy was administered to 12 patients with MT of GCT limited to a single cell type (two patients with primitive neuroectodermal tumors, five with undifferentiated RMS, one with anaplastic small-cell tumor, two with adenocarcinoma, and two with leukemia); 10 patients had measurable disease. GCT origin was confirmed by molecular cytogenetics in five patients. Each patient received chemotherapy regimens based on the specific malignant cell observed in the transformed histology. Seven patients with measurable disease achieved a partial response, with the duration of response ranging between 1 month and 7 years. Three of those patients are alive. Three patients did not respond to treatment, and all of those patients died as a result of their disease. Chemotherapy for MT limited to a single cell type may result in major responses and long-term survival in selected patients. Local therapy after chemotherapy is an important component of treatment to achieve maximum response.

Characterization and tissue-specific expression of human GSK-3-binding proteins FRAT1 and FRAT2

We have isolated the entire coding sequence of human FRAT2 (frequently rearranged in advanced T-cell lymphomas-2). It exhibits appreciable amino acid identity to FRAT1 (77%) which was initially isolated as frequently being overexpressed in a murine leukemia virus insertion model in murine tumors. FRAT proteins are thought to play a role in Wnt signaling. They can bind to glycogen synthase kinase-3 (GSK-3) and Dishevelled, two proteins involved in Wnt signal transduction. Both hFRAT1 and hFRAT2 are intronless genes localized to the same portion of chromosome 10q24.1 and separated by only 10.7 kb. In a broad range of human tissues FRAT1 and FRAT2 are readily detected and expressed in a near identical pattern. Both species are repressed when the human embryonal carcinoma cell line, NT2/D1, is induced to differentiate with all-trans retinoic acid (RA). This treatment had no appreciable effect on FRAT levels in two other RA-sensitive cell lines that were not of germ cell tumor origin. The overlapping expression patterns suggest these two genes share a regulatory region. Both FRAT genes exhibited three species of mRNA, which varied in representation between tissues. When transiently overexpressed in COS-1 cells, the FRAT proteins were detected in the cytosol and concentrated in the nucleus. Both hFRAT1 and hFRAT2 are implicated in the selective modulation of GSK-3 activity via the Wnt signaling pathway. This study provides a foundation from which to examine the role these proteins play in Wnt-dependent and -independent processes.

Metastatic germ cell tumors: modeling for response to chemotherapy.

This study sought to determine factors that predict response to chemotherapy for patients with advanced germ cell tumors (GCTs), to evaluate different methods by which serum tumor markers can be used to predict response independent of assay method, and to develop criteria to guide allocation to clinical trials. Pretreatment data from 796 patients treated with platinum-based chemotherapy on Memorial Hospital protocols from 1975 to 1990 were analyzed. Multivariate analyses were performed on a developmental data set (n = 597) to assess for independently significant predictors of response. Predictive models developed using these methods were confirmed on the validation set (n = 199). Independently significant factors for response included a mediastinal primary tumor (.015), pure seminomatous histology (.002), metastases to nonpulmonary visceral sites (bone, liver, and brain; .0001), and the pretreatment values of lactate dehydrogenase (LDH; .0001) and human chorionic gonadotropin (HCG; .0001). The likelihood of complete response (CR) was increased by seminomatous histology and decreased by the other factors. Serum levels of HCG and LDH could predict outcome independent of assay methodology. A model to predict good-, intermediate-, and poor-risk categories with CR rates of 92%, 76%, and 39%, respectively, was developed. The independent prognostic factors of serum tumor markers LDH and HCG, the sites of metastases, and the primary origin of GCTs can predict outcome in patients with advanced GCT. These factors should be considered in the allocation of patients with advanced disease to clinical trials and have been included in the new tumor-node-metastasis (TNM) staging systems developed for the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer (UICC).

The origin of germ cell tumors of the testis.

Two hundred and eight cases of germ cell tumors of the testis were thoroughly studied. Fifty-one (24.5%) were embryonal carcinoma, 115 (55.3%) were seminoma, and 42 (20.2%) contained both embryonal carcinoma and seminoma. The average age of the patients with embryonal carcinoma, seminoma, and combined tumors was 27.6, 38.3, and 30.3 years. Furthermore, in the patients with combined tumors, those having a predominance of embryonal carcinoma had an average age of 28.3 years, while those having a predominance of seminoma had an average age of 33.4 years. This study supports the concept that the malignant potential of germ cells in younger patients is embryonal carcinoma, the malignant potential of germ cells in older patients is seminoma, and that in intermediate-aged patients the germ cells are capable of developing varying amounts of embryonal carcinoma and seminoma in the same tumor.

Pre-natal factors in the origin of germ cell tumours of childhood.

The Manchester (England) Children's Tumour Registry is population-based with a high level of ascertainment. Pathologic review ensured diagnostic accuracy. Routine monitoring of annual incidence revealed a significant increase in germ cell tumours from approximately 1 per million person years to approximately 4. Analysis of the children's case records and their mothers' obstetric records showed an association between germ cell tumours and congenital malformations, particularly of the central nervous system, in the children themselves and in their stillborn sibs. An association between infections in pregnancy and early onset of tumours in the offspring was demonstrated. Other factors such as chronic illness in the mothers and drug-taking during pregnancy may be important, but further work is required to establish any definite associations.