Molecular and epigenetic ex vivo profiling of testis cancer-associated fibroblasts and their interaction with germ cell tumor cells and macrophages.

Germ cell tumors (GCT) are the most common solid tumors in young men of age 15 - 40. In previous studies, we profiled the interaction of GCT cells with cells of the tumor microenvironment (TM), which showed that especially the 3D interaction of fibroblasts (FB) or macrophages with GCT cells influenced the growth behavior and cisplatin response as well as the transcriptome and secretome of the tumor cells, suggesting that the crosstalk of these cells with GCT cells is crucial for tumor progression and therapy outcome. In this study, we shed light on the mechanisms of activation of cancer-associated fibroblasts (CAF) in the GCT setting and their effects on GCT cells lines and the monocyte cell line THP-1.

Characterization of the dehydrogenase-reductase DHRS2 and its involvement in histone deacetylase inhibition in urological malignancies.

Background: Being implicated during tumor migration, invasion, clonogenicity, and proliferation, the nicotinamide adenine dinucleotide (NAD)/-phosphate (NADP)-dependent dehydrogenase/reductase member 2 (DHRS2) has been considered to be induced upon inhibition of histone deacetylases (HDACi). In this study, we evaluated the current knowledge on the underlying mechanisms of the (epi)genetic regulation of DHRS2, as well as its function during tumor progression.

Methods: DHRS2 expression was evaluated on mRNA- and protein-level upon treatment with HDACi by means of qRT-PCR and western blot analyses, respectively.

Novel meriolin derivatives activate the mitochondrial apoptosis pathway in the presence of antiapoptotic Bcl-2.

Meriolin derivatives represent a new class of kinase inhibitors with a pronounced cytotoxic potential. Here, we investigated a newly synthesized meriolin derivative (termed meriolin 16) that displayed a strong apoptotic potential in Jurkat leukemia and Ramos lymphoma cells. Meriolin 16 induced apoptosis in rapid kinetics (within 2-3 h) and more potently (IC: 50 nM) than the previously described derivatives meriolin 31 and 36 [1].

Assessing the risk to develop a growing teratoma syndrome based on molecular and epigenetic subtyping as well as novel secreted biomarkers.

In germ cell tumors (GCT), a growing teratoma during chemotherapy with decreasing tumor markers was defined as 'growing teratoma syndrome' (GTS) by Logothetis et al. in 1982. So far, its pathogenesis and specific treatment options remain elusive.

CD24 targeting with NK-CAR immunotherapy in testis, prostate, renal and (luminal-type) bladder cancer and identification of direct CD24 interaction partners.

Alternative therapeutic options targeting urologic malignancies, such as germ cell tumours, as well as urothelial, renal and prostate carcinomas, are still urgently needed. The membrane protein CD24 represents a promising immunotherapeutical approach. The present study aimed to decipher the molecular function of CD24 in vitro and evaluate the cytotoxic capacity of a third-generation natural killer (NK) cell chimeric antigen receptor (CAR) against CD24 in urologic tumour cell lines.

Establishment and Evaluation of Dual HDAC/BET Inhibitors as Therapeutic Options for Germ Cell Tumors and Other Urological Malignancies.

Urological malignancies represent major challenges for clinicians, with annually rising incidences. In addition, cisplatin treatment induced long-term toxicities and the development of therapy resistance emphasize the need for novel therapeutics. In this study, we analyzed the effects of novel histone deacetylase (HDAC) and bromodomain and extraterminal domain-containing (BET) inhibitors to combine them into a potent HDAC-BET-fusion molecule and to understand their molecular mode-of-action.

Profiling the 3D interaction between germ cell tumors and microenvironmental cells at the transcriptome and secretome level.

The tumor microenvironment (TM), consisting of the extracellular matrix (ECM), fibroblasts, endothelial cells, and immune cells, might affect tumor invasiveness and the outcome of standard chemotherapy. This study investigated the cross talk between germ cell tumors (GCT) and surrounding TM cells (macrophages, T-lymphocytes, endothelial cells, and fibroblasts) at the transcriptome and secretome level. Using high-throughput approaches of three-dimensional (3D) co-cultured cellular aggregates, this study offers newly identified pathways to be studied with regard to sensitivity toward cisplatin-based chemotherapy or tumor invasiveness as a consequence of the cross talk between tumor cells and TM components.

The developmental origin of cancers defines basic principles of cisplatin resistance.

Cisplatin-based chemotherapy has been used for more than four decades as a standard therapeutic option in several tumor entities. However, being a multifaceted and heterogeneous phenomenon, inherent or acquired resistance to cisplatin remains a major obstacle during the treatment of several solid malignancies and inevitably results in disease progression. Hence, we felt there was an urgent need to evaluate common mechanisms between multifarious cancer entities to identify patient-specific therapeutic strategies.

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).

Molecular and epigenetic pathogenesis of germ cell tumors.

The development of germ cell tumors (GCTs) is a unique pathogenesis occurring at an early developmental stage during specification, migration or colonization of primordial germ cells (PGCs) in the genital ridge. Since driver mutations could not be identified so far, the involvement of the epigenetic machinery during the pathogenesis seems to play a crucial role. Currently, it is investigated whether epigenetic modifications occurring between the omnipotent two-cell stage and the pluripotent implanting PGCs might result in disturbances eventually leading to GCTs.

Prodigiosin Sensitizes Sensitive and Resistant Urothelial Carcinoma Cells to Cisplatin Treatment.

Cisplatin-based treatment is the standard of care therapy for urothelial carcinomas. However, complex cisplatin resistance mechanisms limit the success of this approach. Both apoptosis and autophagy have been shown to contribute to this resistance.

The pioneer and differentiation factor FOXA2 is a key driver of yolk-sac tumour formation and a new biomarker for paediatric and adult yolk-sac tumours.

Yolk-sac tumours (YSTs), a germ cell tumour subtype, occur in newborns and infants as well as in young adults of age 14-44 years. In clinics, adult patients with YSTs face a poor prognosis, as these tumours are often therapy-resistant and count for many germ cell tumour related deaths. So far, the molecular and (epi)genetic mechanisms that control development of YST are far from being understood.

Evaluation of Chemotherapeutic Drugs for Treatment of (Cisplatin-Resistant) Germ Cell Cancer Cell Lines.

Cisplatin resistance still remains a major obstacle in the standard chemotherapeutic approach in late-stage and metastatic testicular germ cell cancer (GCC) patients. This multifactorial and complex phenomenon arises (concomitantly) on several levels due to impaired transport, decreased adduct formation, increased DNA-repair, decreased apoptosis, or compensating pathways. Evaluation of novel therapeutic approaches and pharmacological inhibitors still remains necessary to treat cisplatin-resistant GCCs.

Three-Dimensional Cultivation of Germ Cell Cancer Cell Lines as Hanging Drops.

The hanging drop cell culture technique allows to study three-dimensional growth and differentiation of cell aggregates, that is, embryonic stem cells. Compared to standard two-dimensional monolayer cell cultivation, hanging drops allow for a better visualization and understanding of the developmental processes in vitro. Hanging drop cultivation can also be used to study biology of cancer cells three-dimensionally in vitro.

CDK4/6 inhibition presents as a therapeutic option for paediatric and adult germ cell tumours and induces cell cycle arrest and apoptosis via canonical and non-canonical mechanisms.

Background: Germ cell tumours (GCTs) are the most common solid malignancies in young men. Although high cure rates can be achieved, metastases, resistance to cisplatin-based therapy and late toxicities still represent a lethal threat, arguing for the need of new therapeutic options. In this study, we analysed the potential of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors palbociclib and ribociclib (PaRi) as molecular drugs to treat cisplatin-resistant and -sensitive paediatric and adult GCTs.

Regulates Transcription and the Epigenetic Landscape via POLE and DMAP1 while Deficiency or Pharmacological Inhibition Sensitizes Germ Cell Tumor Cells to ATR Inhibition.

Germ cell tumors (GCTs) are the most common solid malignancies found in young men. Although they generally have high cure rates, metastases, resistance to cisplatin-based therapy, and late toxicities still represent a lethal threat, arguing for the need of new therapeutic options. In a previous study, we identified downregulation of the chromatin-remodeling SWI/SNF complex member ARID1A as a key event in the mode of action of the histone deacetylase inhibitor romidepsin.

Distinctive mutational spectrum and karyotype disruption in long-term cisplatin-treated urothelial carcinoma cell lines.

The DNA-damaging compound cisplatin is broadly employed for cancer chemotherapy. The mutagenic effects of cisplatin on cancer cell genomes are poorly studied and might even contribute to drug resistance. We have therefore analyzed mutations and chromosomal alterations in four cisplatin-resistant bladder cancer cell lines (LTTs) by whole-exome-sequencing and array-CGH.

Deciphering the molecular effects of romidepsin on germ cell tumours: DHRS2 is involved in cell cycle arrest but not apoptosis or induction of romidepsin effectors.

Testicular germ cell tumours (GCTs) mostly affect young men at age 17-40. Although high cure rates can be achieved by orchiectomy and chemotherapy, GCTs can still be a lethal threat to young patients with metastases or therapy resistance. Thus, alternative treatment options are needed.

Multifaceted Mechanisms of Cisplatin Resistance in Long-Term Treated Urothelial Carcinoma Cell Lines.

Therapeutic efficacy of cisplatin-based treatment of late stage urothelial carcinoma (UC) is limited by chemoresistance. To elucidate underlying mechanisms and to develop new approaches for overcoming resistance, we generated long-term cisplatin treated (LTT) UC cell lines, characterised their cisplatin response, and determined the expression of molecules involved in cisplatin transport and detoxification, DNA repair, and apoptosis. Inhibitors of metallothioneins and Survivin were applied to investigate their ability to sensitise towards cisplatin.

Targeting urothelial carcinoma cells by combining cisplatin with a specific inhibitor of the autophagy-inducing class III PtdIns3K complex.

Background: Cisplatin-based regimens are routinely employed for the treatment of urothelial carcinoma. However, therapeutic success is hampered by the primary presence of or the development of cisplatin resistance. This chemoresistance is executed by multiple cellular pathways.

Blocking 17β-hydroxysteroid dehydrogenase type 1 in endometrial cancer: a potential novel endocrine therapeutic approach.

The enzyme type 1 17β-hydroxysteroid dehydrogenase (17β-HSD-1), responsible for generating active 17β-estradiol (E2) from low-active estrone (E1), is overexpressed in endometrial cancer (EC), thus implicating an increased intra-tissue generation of E2 in this estrogen-dependent condition. In this study, we explored the possibility of inhibiting 17β-HSD-1 and impairing the generation of E2 from E1 in EC using in vitro, in vivo, and ex vivo models. We generated EC cell lines derived from the well-differentiated endometrial adenocarcinoma Ishikawa cell line and expressing levels of 17β-HSD-1 similar to human tissues.