Browsing by Author "Fichtner, Alexander"

Testicular germ cell cancer (TGCC) is the most common type of cancer in young men. Seminomas account for around half of them and are characterized by a pronounced infiltration of immune cells. So far, the impact of the tumor microenvironment (TME) on disease progression, especially the interaction of individual immune cell subtypes with the tumor cells, remains unclear. To address this question, we used an in vitro TME model involving the seminoma-derived cell line Tcam-2 and immune cell subsets purified from human peripheral blood. T cells and monocytes were strongly activated when individually cocultured with Tcam-2 cells as revealed by increased expression of activation markers and pro-inflammatory cytokines both on the mRNA and protein level. Importantly, the interaction between tumor and immune cells was mutual. Gene expression of pluripotency markers as well as markers of proliferation and cell cycle activity were upregulated in Tcam-2 cells in cocultures with T cells, whereas gene expression of SOX17, a marker for seminomas, was unaltered. Interestingly, the impact of monocytes on gene expression of Tcam-2 cells was less pronounced, indicating that the effects of individual immune cell subsets on tumor cells in the TME are highly specific. Collectively, our data indicate that seminoma cells induce immune cell activation and thereby generate a strong pro-inflammatory milieu, whereas T cells conversely increase the proliferation, metastatic potential, and stemness of tumor cells. Although the employed model does not fully mimic the physiological situation found in TGCC in vivo, it provides new insights potentially explaining the connection between inflammatory infiltrates in seminomas and their tendency to burn out and metastasize.

Die große Vielfalt der histologischen Muster von Keimzelltumoren, insbesondere beim Dottersacktumor, aber auch das Phänomen der somatischen Malignität können die tägliche Diagnostik komplizieren. Verschiedene morphologische Aspekte und immunhistochemische Zusatzuntersuchungen können bei der Diagnosefindung hilfreich sein. Auch das Spektrum seltener Entitäten wie Gonadenstromatumoren, testikuläre Adnextumoren und Weichgewebstumoren des Samenstrangs können zu einer diagnostischen Herausforderung werden.

Introduction Data on the efficacy and safety of everolimus in pediatric renal transplantation compared to other immunosuppressive regimens are scarce. Patients/Methods We therefore performed a multicenter, observational, matched cohort study over 4 years post-transplant in 35 patients on everolimus plus low-dose cyclosporine, who were matched (1: 2) with a control group of 70 children receiving a standard-dose calcineurin-inhibitor-and mycophenolate mofetil-based regimen. Results Corticosteroids were withdrawn in 83% in the everolimus vs. 39% in the control group (p<0.001). Patient and graft survival were comparable. The rate of biopsy-proven acute rejection episodes Banff score >= IA during the first year post-transplant was 6% in the everolimus vs. 13% in the control group (p = 0.23). The rate of de novo donor-specific HLA antibodies (11% in everolimus, 18% in controls) was comparable (p = 0.55). At 4 years post-transplant, mean eGFR in the everolimus group was 56 +/- 33 ml/min per 1.73 m(2) vs. 63 +/- 22 ml/min per 1.73 m(2) in the control group (p = 0.14). Everolimus therapy was associated with less BK polyomavirus replication (3% vs. 17% in controls; p = 0.04), but with a higher percentage of arterial hypertension and more hyperlipidemia (p<0.001). Conclusion In pediatric renal transplantation, an everolimus-based regimen with low-dose cyclosporine yields comparable four year results as a standard regimen, but with a different side effect profile.

Zusammenfassung Die Keimzelltumoren machen den Großteil der Hodentumoren aus und bilden eine heterogene Gruppe an Tumoren, die sich biologisch unterschiedlich verhalten. Aufgrund des Auftretens in unterschiedlichen Altersgruppen, ihrer morphologischen Charakteristika und der molekularen Veränderungen werden sie in 3 verschiedene Gruppen (Typ I–III) unterteilt. Die genaue histopathologische Analyse eines Orchiektomieresektats, die Zuordnung in die genannten 3 Gruppen und die genaue Benennung aller Subtypen mit prozentualer Verteilung ist für die Therapie und Prognose eines Patienten mit Keimzelltumor sehr wichtig. In diesem Artikel wird die Vorgehensweise bei der Aufarbeitung eines Orchiektomieresektats und die histopathologische Analyse des Hodentumorgewebes geschildert und dargestellt, in welchen Situationen Hilfsmittel wie immunhistochemische oder molekularpathologische Untersuchungen notwendig sind. Ferner wird die aktuelle Einteilung der Keimzelltumoren des Hodens anhand der gültigen WHO-Klassifikation geschildert und diskutiert.

In der 5. Edition der WHO-Klassifikation für Tumoren der ableitenden Harnwege und des männlichen Genitaltraktes gab es einige Neuerungen der bestehenden Klassifikationen. Sie werden in diesem Artikel zusammengefasst und betreffen u. a. die Bezeichnungen neuroektodermaler und neuroendokriner Tumoren des Hodens. Daneben wurden der siegelringzellige Stromatumor und der myoidale Gonadenstromatumor als eigenständige Entitäten der Gonadenstromatumoren eingeführt. Außerdem wurden jeweils gemeinsame Kapitel für hämatolymphoide Neoplasien sowie Weichgewebstumoren der ableitenden Harnwege und des männlichen Genitaltraktes geschaffen.

Testicular germ cell tumours (GCT) are divided into three different subtypes (types I–III) regarding to their developmental origin, histological differences and molecular features. Type I GCT develop from disturbed primordial germ cells and most commonly occur in children and young adolescents, which is why they are referred to as prepubertal GCT. Type II GCT develop from a non‐invasive germ cell neoplasia in situ (GCNIS) and show an isochromosome 12p (i12p) or gain of 12p material as a common and characteristic molecular alteration. Type III GCT originate from distorted postpubertal germ cells (e.g. spermatogonia) in adult patients and have changes on chromosome 9 with amplification of the DMRT1 gene. Type I GCT encompass prepubertal‐type teratomas and yolk‐sac tumours (YST). Type II GCT include seminoma, embryonal carcinoma, choriocarcinoma, postpubertal‐type teratoma and postpubertal‐type YST. Types I and II GCT both show similar morphology, but are separated from each other by the detection of a GCNIS and an i12p in type II GCT. For type II GCT it is especially important to detect non‐seminomatous elements, as these tumours have a worse biological behaviour and need a different treatment to seminomas. In contrast to types I and II GCT, type III tumours are equivalent to spermatocytic tumours and usually occur in elderly men, with few exceptions in young adults. The development of types I and II GCT seems to depend not upon driver mutations, but rather on changes in the epigenetic landscape. Furthermore, different pluripotency associated factors (e.g. OCT3/4, SOX2, SOX17) play a crucial role in GCT development and can be used as immunohistochemical markers allowing to distinguish the different subtypes from each other in morphologically challenging tissue specimens. Especially in metastatic sites, a morphological and immunohistochemical diagnostic algorithm is important to detect small subpopulations of each non‐seminomatous GCT subtype, which are associated with a poorer prognosis and need a different treatment. Furthermore, primary extragonadal GCT of the retroperitoneum or mediastinum develop from misguided germ cells during embryonic development, and might be challenging to detect in small tissue biopsies due to their rarity at corresponding sites. This review article summarises the pathobiological and developmental aspects of the three different types of testicular GCT that can be helpful in the histopathological examination of tumour specimens by pathologists.

Abstract Background Testicular germ cell tumor (TGCT) is the most common type of tumor in young men. Type II germ cell tumors including postpubertal‐type teratomas are derived from the germ cell neoplasia in situ (GCNIS), whereas prepubertal‐type teratomas arise independently of the GCNIS. The consomic mouse strain 129.MOLF‐Chr19 (M19) is a suitable murine model of such tumors, but its characterization remains incomplete. Objective Here, we interrogated the suitability of testicular tumors in M19 mice as a model of human TGCT by analyzing their histological features and gene expression signature. Material and methods Testes collected from M19 mice of different ages were categorized by macroscopic appearance based on size and the degree of suspected tumorigenesis. Histological sections from selected tumors were stained with Hematoxylin and Eosin, and expression of genes associated with tumorigenesis was determined in frozen tissue samples from a large range of tumors of different subclasses using RT‐qPCR and Fluidigm Dynamic Arrays. Results Macroscopically, testicular specimens appeared very heterogeneous concerning size and signs indicating the presence of a tumor. Histological analysis confirmed the development of teratomas with areas of cells corresponding to all three germ cell layers. Gene expression analyses indicated upregulation of markers related to proliferation, vascular invasive potential and pluripotency, and revealed a strong correlation of gene expression with tumor size and a significant intercorrelation of individual genes. Discussion and conclusion TGCT in M19 mice is reminiscent of human testicular teratomas presenting with areas of cells derived from all germ layers and showing a typical gene signature. We thus confirm that these mice can serve as a suitable murine model of pure teratomas for preclinical research.

This article will review current aspects of the histopathological, immunohistochemical and molecular analysis of primary mediastinal germ cell tumours (PMGCTs) as well as their aetiological, epidemiological, clinical and therapeutic features. PMGCTs represent an important differential diagnosis in the spectrum of mediastinal tumours, and their diagnosis is usually made on small tissue samples from core needle biopsies in combination with diagnostic imaging and serum tumour markers. As in lymphomas, a small biopsy is often the only viable tumour sample available from these patients, as they receive chemotherapy prior to eventual surgical resection. Pathologists therefore need to apply an efficient combination of immunohistochemical markers to confirm the diagnosis of a PMGCT and to exclude morphological mimics.

Aims Primary mediastinal germ cell tumours (PMGCTs) are rare mediastinal neoplasms, and their diagnosis can be challenging, owing to small biopsy samples. The aim of this study was to develop a diagnostic algorithm using immunohistochemical staining, with a focus on novel markers, and molecular analysis of isochromosome 12p [i(12p)]. Methods and results Paraffin‐embedded tissues of 32 mediastinal tumours were analysed with immunohistochemical staining for sal‐like transcription factor 4 (SALL4), Lin‐28 homologue A (LIN28), octamer‐binding transcription factor 3/4 (OCT3/4), D2‐40, cluster of differentiation 117 (CD117), sex‐determining region Y‐box 17, sex‐determining region Y‐box 2 (SOX2), cluster of differentiation 30, the β‐subunit of human chorionic gonadotropin (β‐hCG), GATA‐binding protein 3 (GATA3), forkhead box protein A2 (FOXA2), glypican‐3 (GPC3), α‐fetoprotein (AFP), terminal deoxynucleotidyl transferase (TdT), nuclear protein of the testis (NUT), and pan‐cytokeratin. Quantitative real‐time polymerase chain reaction was performed to investigate the i(12p) status. Fifteen seminomas, seven teratomas, one yolk sac tumour, one choriocarcinoma and seven mixed PMGCTs were diagnosed. Each entity had different immunohistochemical staining patterns, which helped to distinguish them: OCT3/4, D2‐40, CD117 and TdT for seminoma; OCT3/4 and SOX2 for embryonal carcinoma; FOXA2, GPC3 and AFP for yolk sac tumour; and β‐hCG and GATA3 for choriocarcinoma. Mature teratomas stained positively for pan‐cytokeratin in epithelial components and focally for SALL4, SOX2, GATA3, D2‐40, and FOXA2. Furthermore, a NUT carcinoma mimicking a PMGCT was diagnosed, showing strong nuclear SOX2 staining and speckled nuclear NUT staining. i(12p) was detected in 24 of 27 PMGCTs (89%). Conclusion A diagnostic algorithm is of great importance for a reliable diagnosis of PMGCT in, usually small, tissue biopsy samples. Therefore, a combination of three to four antibodies to identify the correct histological subtype is usually necessary, in addition to morphological features. The i(12p) status serves as an additional option to indicate a germ cell origin in selected cases.

Abstract The differentiation between a pulmonary metastasis and a newly developed squamous cell carcinoma of the lung in patients with prior head and neck squamous cell carcinoma (HNSCC) is difficult due to a lack of biomarkers but is crucially important for the prognosis and therapy of the affected patient. By using high‐resolution mass spectrometry in combination with stable isotope labelling by amino acids in cell culture, we identified 379 proteins that are differentially expressed in squamous cell carcinomas of the lung and the head and neck. Of those, CAV1, CAV2, LGALS1, LGALS7, CK19, and UGDH were tested by immunohistochemistry on 194 tissue samples (98 lung and 96 HNSCCs). The combination of CAV1 and LGALS7 was able to distinguish the origin of the squamous cell carcinoma with high accuracy (area under the curve 0.876). This biomarker panel was tested on a cohort of 12 clinically classified lung tumours of unknown origin after HNSCC. Nine of those tumours were immunohistochemically classifiable.

Aims Malignant germ cell tumours (GCTs) of the testis are rare neoplasms, but the most common solid malignancies in young men. World Health Organization guidelines divide GCTs into five types, for which numerous immunohistochemical markers allow exact histological subtyping in the majority of cases. In contrast, a germ cell origin is often hard to prove in metastatic GCTs that have developed so‐called somatic malignant transformation. A high percentage, up to 89%, of GCTs are characterised by the appearance of isochromosome 12p [i(12p)]. Fluorescence in‐situ hybridisation has been the most common diagnostic method for the detection of i(12p) so far, but has the disadvantages of being time‐consuming, demanding, and not being a stand‐alone method. The aim of the present study was to establish a quantitative real‐time polymerase chain reaction assay as an independent method for detecting i(12p) and regional amplifications of the short arm of chromosome 12 by using DNA extracted from formalin‐fixed paraffin‐embedded tissue. Methods and results A cut‐off value to distinguish between the presence and absence of i(12p) was established in a control set consisting of 36 tumour‐free samples. In a training set of 149 GCT samples, i(12p) was detectable in 133 tumours (89%), but not in 16 tumours (11%). In a test set containing 27 primary and metastatic GCTs, all 16 tumours with metastatic spread and/or somatic malignant transformation were successfully identified by the detection of i(12p). Conclusion In summary, the qPCR assay presented here can help to identify, further characterise and assign a large proportion of histologically inconclusive malignancies to a GCT origin.

Abstract Sentinel lymph node (SN) tumor burden is becoming increasingly important and is likely to be included in future N classifications in melanoma. Our aim was to investigate the prognostic significance of melanoma infiltration of various anatomically defined lymph node substructures. This retrospective cohort study included 1250 consecutive patients with SN biopsy. The pathology protocol required description of metastatic infiltration of each of the following lymph node substructures: intracapsular lymph vessels, subcapsular and transverse sinuses, cortex, paracortex, medulla, and capsule. Within the SN with the highest tumor burden, the SN invasion level (SNIL) was defined as follows: SNIL 1 = melanoma cells confined to intracapsular lymph vessels, subcapsular or transverse sinuses; SNIL 2 = melanoma infiltrating the cortex or paracortex; SNIL 3 = melanoma infiltrating the medulla or capsule. We classified 338 SN-positive patients according to the non-metric SNIL. Using Kaplan–Meier estimates and Cox models, recurrence-free survival (RFS), melanoma-specific survival (MSS) and nodal basin recurrence rates were analyzed. The median follow-up time was 75 months. The SNIL divided the SN-positive population into three groups with significantly different RFS, MSS, and nodal basin recurrence probabilities. The MSS of patients with SNIL 1 was virtually identical to that of SN-negative patients, whereas outgrowth of the metastasis from the parenchyma into the fibrous capsule or the medulla of the lymph node indicated a very poor prognosis. Thus, the SNIL may help to better assess the benefit-risk ratio of adjuvant therapies in patients with different SN metastasis patterns.

Testicular germ cell cancer (TGCC) is subdivided into several subtypes. While seminomatous germ cell tumors (SGCT) are characterized by an intensive infiltration of immune cells which constitute a pro-inflammatory tumor micromilieu (TME), immune cells in non-seminomatous germ cell tumors (NSGCT) are differently composed and less abundant. Previously, we have shown that the seminomatous cell line TCam-2 promotes T cell and monocyte activation in a coculture model, resulting in mutual interactions between both cell types. Here we set out to compare this feature of TCam-2 cells with the non-seminomatous cell line NTERA-2. Peripheral blood T cells or monocytes cocultured with NTERA-2 cells failed to secrete relevant amounts of pro-inflammatory cytokines, and significantly downregulated the expression of genes encoding activation markers and effector molecules. In contrast, immune cells cocultured with TCam-2 cells produced IL-2, IL-6 and TNFα, and strongly upregulated the expression of multiple pro-inflammatory genes. Furthermore, the expression of genes involved in proliferation, stemness and subtype specification remained unaltered in NTERA-2 cells during coculture with T cells or monocytes, indicating the absence of mutual interactions. Collectively, our findings uncover fundamental differences between SGCT and NSGCT in their capability to generate a pro-inflammatory TME, which possibly impacts the clinical features and prognosis of both TGCC subtypes.